Alexis Sanchez scored twice as Arsenal beat West Brom to strengthen their hopes of a top-four finish.

Media playback is not supported on this device
The Gunners had drawn their previous two games but Sanchez settled the nerves with a neat finish on the turn from outside the area.
West Brom's Gareth McAuley hit the bar with a header but that was as close as they came to a goal.
And Sanchez's driven free-kick secured the win for Arsenal, who move up to third, five points behind Tottenham.
The win helps ease concerns the Gunners could miss out on the top four - they are now four points clear of Manchester United in fifth.
Relive Arsenal's win over West Brom.
Striving to stay in the top four is a far cry from how Arsenal's fans would have imagined this season finishing considering their position on New Year's Day, when they were top of the table.
The north London club were ideally positioned to challenge for a first Premier League title in 12 years, but a run of just five wins in 2016 prior to the visit of West Brom all but ended their hopes.
A disappointing 1-1 draw at home to Crystal Palace on Sunday left the Gunners 13 points behind leaders Leicester and some fans had made their discontent clear with boos at the final whistle at the weekend.
Fan apathy was evident in the number of empty seats at Emirates Stadium on Thursday, and there was an eerie atmosphere when the game got under way.
An early goal was needed to ease the tension and Sanchez duly stepped up to deliver with a finish of real quality. The forward received a pass from Mesut Ozil and turned Sandro before firing beyond Ben Foster.
The Chilean was at his marauding best and he continued to torment West Brom before deservedly scoring a second, driving a free-kick through the West Brom wall.
Under Tony Pulis, West Brom have hardly been prolific. They have scored just 50 goals in 51 games and have had the fewest shots on target in the Premier League this season with 93.
Add that to the fact they had lost all but one of their nine previous Premier League trips to Arsenal, and a victory for the visitors looked a tall order.
Their best chances came from set pieces. McAuley rattled the bar from a corner when the score was 1-0, while Salomon Rondon missed a near open goal from another corner midway through the second half.
From open play they carried no threat but with the Baggies 15th and 10 points clear of trouble, their job is largely done.
This game was the first for referee Jon Moss since his controversial performance in the 2-2 draw between leaders Leicester and West Ham on Sunday.
Moss awarded two penalties in that game, and also gave Foxes striker Jamie Vardy a second yellow card for diving.
On Thursday, Moss waved away a West Brom appeal for a penalty when Sanchez appeared to handle inside the area, and also took no action when Arsenal's Mohamed Elneny went down easily inside the area despite there being no contact by a defender.
He issued just the one yellow card and that was to McAuley after the Baggies defender held Olivier Giroud just before half-time.
Media playback is not supported on this device
Arsenal boss Arsene Wenger: "We did the job in a serious way. We played well technically and the only regret is we should have scored more goals.
"The early goal helped us not be be anxious about the consequence of the result.
"We are in a position where it depends on us to finish in the top three but we want more and we have to fight to do that and if possible do more."
West Brom manager Tony Pulis: "We didn't play as well as we can. We had too many players off it, which you can't do at Arsenal.
Media playback is not supported on this device
"The players have given me everything this year. We have played well at all of the big teams but not tonight. Sometimes you have to take defeat on the chin."
Arsenal travel to struggling Sunderland on Sunday, while West Brom are at Tottenham on Monday.
Match ends, Arsenal 2, West Bromwich Albion 0.
Second Half ends, Arsenal 2, West Bromwich Albion 0.
Foul by Joel Campbell (Arsenal).
Craig Dawson (West Bromwich Albion) wins a free kick in the defensive half.
Offside, Arsenal. Joel Campbell tries a through ball, but Olivier Giroud is caught offside.
Foul by Nacho Monreal (Arsenal).
Stéphane Sessegnon (West Bromwich Albion) wins a free kick in the defensive half.
Attempt missed. Olivier Giroud (Arsenal) right footed shot from the centre of the box misses to the right. Assisted by Joel Campbell.
Attempt saved. Olivier Giroud (Arsenal) left footed shot from the left side of the box is saved in the top left corner. Assisted by Joel Campbell.
Attempt missed. Joel Campbell (Arsenal) left footed shot from the left side of the box misses to the right. Assisted by Aaron Ramsey.
Substitution, Arsenal. Joel Campbell replaces Mesut Özil.
Substitution, Arsenal. Theo Walcott replaces Alexis Sánchez.
Attempt missed. Claudio Yacob (West Bromwich Albion) right footed shot from outside the box misses to the left.
Aaron Ramsey (Arsenal) wins a free kick in the attacking half.
Foul by Claudio Yacob (West Bromwich Albion).
Substitution, Arsenal. Francis Coquelin replaces Alex Iwobi.
Alexis Sánchez (Arsenal) wins a free kick on the right wing.
Foul by Jonny Evans (West Bromwich Albion).
Attempt blocked. Craig Gardner (West Bromwich Albion) right footed shot from outside the box is blocked. Assisted by Salomón Rondón.
Foul by Laurent Koscielny (Arsenal).
Salomón Rondón (West Bromwich Albion) wins a free kick in the defensive half.
Delay over. They are ready to continue.
Delay in match Mohamed Elneny (Arsenal) because of an injury.
Attempt missed. Jonny Evans (West Bromwich Albion) left footed shot from outside the box misses to the right following a set piece situation.
Foul by Alexis Sánchez (Arsenal).
Craig Dawson (West Bromwich Albion) wins a free kick on the right wing.
Attempt missed. Salomón Rondón (West Bromwich Albion) right footed shot from very close range misses to the right. Assisted by Craig Gardner with a cross following a corner.
Corner,  West Bromwich Albion. Conceded by Per Mertesacker.
Attempt saved. Alex Iwobi (Arsenal) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Olivier Giroud.
Corner,  Arsenal. Conceded by Jonas Olsson.
Attempt blocked. Alexis Sánchez (Arsenal) left footed shot from the right side of the box is blocked. Assisted by Alex Iwobi.
Attempt saved. Mesut Özil (Arsenal) right footed shot from the right side of the six yard box is saved in the centre of the goal. Assisted by Alexis Sánchez.
Substitution, West Bromwich Albion. Craig Gardner replaces James McClean.
Foul by Olivier Giroud (Arsenal).
James McClean (West Bromwich Albion) wins a free kick in the defensive half.
Attempt blocked. Olivier Giroud (Arsenal) left footed shot from the centre of the box is blocked. Assisted by Mesut Özil with a cross.
Corner,  Arsenal. Conceded by Craig Dawson.
Nacho Monreal (Arsenal) wins a free kick in the defensive half.
Foul by Salomón Rondón (West Bromwich Albion).
Foul by Nacho Monreal (Arsenal).


Deutsche Bank shareholders have delivered a strong vote of disapproval on the running of the company.

At the German banking giant's annual meeting, 39% of investors refused to support the performances of the co-chief executives.
Germany's corporate governance code gives investors a vote to ratify executives' performance over the year.
Last time, the chief executives won the support of 89% of investors attending the meeting.
Investors have been uneasy about Deutsche's profit growth, mounting regulatory fines, and restructuring plans.
Hermes Equity Ownership Services, which holds a stake in Deutsche Bank of almost 5%, publicly criticised the board ahead of the meeting.
"We no longer have confidence in the management board," said Hermes' director Dr Hans-Christoph Hirt.
The bank said it needed more time to carry out its planned restructuring, and unveiled a management shake-up that gave more power to co-chief executive Anshu Jain.
Deutsche also removed some executives and re-arranged responsibilities.
In response to criticism of the bank's performance, co-chief executive JÃ¼rgen Fitschen said: "We have not delivered, so far, the returns you expect and deserve.
"However, we are convinced: we are moving Deutsche Bank in the right direction. For that reason, we ask for your continued support."


New Liberal Democrat leader Tim Farron says he "absolutely supports equality" amid questions over his Christian faith and politics.

Earlier this week, he refused to answer the question of whether he believed homosexual sex was a sin.
But he told the BBC's Andrew Marr Show he was "passionate about LGBT-plus rights" and defending equal marriage would be "at the top of my agenda".
He also said he wanted to extend the marital rights of transgender people.
Appearing on Channel 4 News on Friday, Mr Farron, who beat Norman Lamb to the leadership, was asked three times if he believed homosexual sex was a sin.
Each time, he refused to give a direct answer, instead choosing to say "my firm belief is we are all sinners".
Mr Farron was asked by Andrew Marr why he voted against the Equality Bill in 2007 - a law which would have made it harder for businesses to discriminate against gay people.
"Let me be crystal clear, I'm a liberal and I absolutely support equality," he replied.
"I'm passionate about LGBT-plus rights, for example, and as the leader of a liberal party, that is something that will be at the top of my agenda throughout the time that I am leader of our party.
"Not just defending the law on equal marriage, but also saying there are areas where it needs to be extended."
Mr Farron said transgender people currently did not have equal access to marriage due to something known as the spousal veto - which means the husband or wife of someone who has changed gender must give their consent in order for the marriage to continue.
He said the Lib Dems tabled an amendment to the Equality Bill because of concerns about "protection of individual liberties" and when that was defeated he voted against the bill.
He did not answer directly when asked what those concerns were, but said: "I am absolutely in favour of equal access under law for all people whatever their sexuality."


EL James' new Fifty Shades of Grey spin-off novel has broken the first week UK sales record for adult books.

Grey sold 647,401 copies in its first three days, beating record holder Dan Brown's The Lost Symbol, which sold 551,000 copies in five days in 2009.
The book tells the same Fifty Shades story but from the perspective of male protagonist Christian Grey.
Despite being savaged by critics, it has become a hit in the US, selling more than 1.1 million in four days.
The figures take in paperback, audio and ebook editions.
"We've had magnificent support from across the trade," said Susan Sandon from publishers Cornerstone.
"The excitement and enthusiasm that Grey's publication has generated is totally irresistible and I am delighted with these early results."
James's Fifty Shades trilogy has been the publishing story of the decade, having now sold more than 125 million copies and spawning a record-breaking film starring Jamie Dornan and Dakota Johnson.
The author announced new novel Grey on 1 June, crediting its existence to persistent fans who had begged her for more from Mr Grey and love interest Anastasia Steele.
It immediately topped book charts from pre-sale orders before being released last week.
Many reviews criticised the novel, including The Telegraph's Bryony Gordon who found the story "as sexy as a misery memoir" in her one-star review.
Author Jenny Colgan writing in The Guardian said - despite it being "rather fun" - it was "almost impossible to read Grey and not assume the narrator is going to end up in jail".
James' publishers also announced today the author will be taking part in a live Twitter Q&A in London on 29 June.


An "upstanding citizen" given an MBE for services to a Fife town has been jailed for nine months for sexual abuse at a children's home.

Trevor Francis, 71, was found guilty of two offences of using lewd, indecent and libidinous practices and behaviour towards young girls and three assaults.
The children were in his care at the St Margaret's children's home in Elie, Fife, in the mid-1970s.
He was given an MBE at Buckingham Palace by Prince Charles in 2012.
At Dundee Sheriff Court a sheriff told him: "This was a gross breach of trust."
Francis, a qualified nurse, took over as a manager at the home in 1973.
He was described as "creepy" and a "Jekyll and Hyde character" who subjected kids there to brutal physical attacks and sexual assaults.
Three girls - aged 14 to 16 at the time- told a jury Francis would creep into the girls' dormitory at the home in the night and sexually assault them.
A male resident at the home told how he had once run away and got as far as Kirkcaldy where he was picked up by police and taken back.
Francis took him into a laundry room and attacked him as punishment.
Other victims told how Francis slapped them in the face and beat them with a slipper in violent rages.
Fiscal depute Eilidh Robertson told the jury: "He is a manipulative, violent and predatory person who abused the trust of these vulnerable people who he was paid to protect.
"But instead he perpetrated physical and sexual abuse towards them and managed to stay undetected because of his Jekyll and Hyde personality.
"The accused might seem mild mannered - an upstanding citizen, a family man.
"We are dealing with an intelligent, manipulative man who can turn on and off that predatory, violent behaviour."
Giving evidence in his own defence Francis said he was "relatively easy going" and claimed to have had a good relationship with the children at the home.
Francis, from Aberdour, had denied a total of nine charges on indictment.
However, a jury found him guilty by majority.
Defence solicitor Kerr Sneddon said: "He maintains his innocence. He therefore can't take responsibility for his actions."
Sheriff Alastair Brown also placed him on the sex offenders register for 10 years.


Torquay United player-manager Kevin Nicholson says goalkeeper Brendan Moore tops his list of players he would like to sign for next season.

The 24-year-old American joined the National League side on loan from Fleetwood in March, playing 12 games.
"Brendan is my number one choice at the moment to get back in," Nicholson said.
"I'll work as best I can to get Brendan back in - he enjoyed it here and I think he's keen, he's just having a look to see what else is out there."
Nicholson, who signed a new three-year deal last week, also revealed he will remain registered as a player after guiding the Gulls to safety.
But Iffy Allen and Danny Racchi were among the players to be released by the Devon club on Monday.
"Some of the lads, it was probably very very unfortunate that I couldn't offer them anything - with a bigger budget things might've been a bit different," added Nicholson to BBC Sport.
"I've got a big list of players already - players that I want to get in regardless and players that are back-up if some of my current players say that they're not going to stay.
"I'm just ploughing on as I should - I'm hoping to get as much done in the next week or so as I can."


The performance of every care home in England can now be compared on an NHS website.

Homes have been added to My NHS, part the NHS Choices site, allowing users to leave ratings and reviews to help other people assess services.
Each care home is scored on its level of safety, staff turnover and food hygiene, among other standards.
The National Care Association said if information was not up to date, it could be "unfair" to care providers.
On the website, a database can be searched using a postcode, region or home name to check on facilities with or without nursing.
People can access:
Health Minister Alistair Burt said:  "We know how difficult important decisions about care for a loved one can be - this is a victory for those who are worried about care - with a click of a button the public will be able to make an informed choice about care and make those difficult decisions easier.
"This data will show clearly the difference in quality across care homes and will help drive up standards by highlighting poor performers which will mean they have to shape up their services or lose out."
Nadra Ahmed, chair of the National Care Association, which represents independent care sector providers, said the move could help people "answer some of the questions" they may have about care.
But she warned that if the "snapshot" of the provider's rating or profile on the site was not regularly updated it could disadvantage those who improve their service.
"I don't know how [improvements] would be indicated... especially if that report is not going to be reviewed for a period of time, which would be unfair."
She added: "Nothing beats actually going to see a service for yourself. If you think that it's good [but the website] says there's something that's not quite right, don't let it put you off.
"When you look at the website you know that responsible services who may have an inadequate rating will be working towards making that better."


Champions Ireland retained their Six Nations title on points difference after an extraordinary final day.

Media playback is not supported on this device
The last round of games concluded with England falling agonisingly short of the 26-point winning margin they needed as they beat France 55-35 in an epic.
The day had started with Wales annihilating Italy 61-20 in Rome.
Ireland needed a huge win and their 40-10 demolition of Scotland was enough to both pass Wales and set a target just beyond England.
With three teams on three wins apiece going into the final round of games the stage was set, and what followed was one of the most incredible days in the tournament since it was first played in 1883, with 221 points scored in the three matches.
England started Saturday as leaders - just - from Ireland on points difference with Wales some way further back, and they would play in reverse order to decide who would become champions.
In the opener, Wales only led Italy by a point at half-time in Rome but cut loose in the second half, with George North's hat-trick ensuring Ireland needed to beat Scotland by 21 points to take the lead on points difference.
The champions duly hammered Scotland by 30 points in Edinburgh, meaning Wales were out of contention and that England needed to beat France by 26 points to take the title.
In a see-saw encounter at Twickenham, England pulled steadily clear but never managed to get into a lead that would have denied Ireland the title.
However, Jack Nowell's try with five minutes remaining put them 20 points ahead and meant a converted try would have given them the Championship.
They spent the closing moments hammering away at the French line in search of the winning points, and came within a foot of scoring, but in their desperation they infringed and the final whistle meant that although they had won handsomely, it was Ireland who are 2015 Six Nations champions.
Ireland captain Paul O'Connell: "I never would have predicted such a game at Twickenham. Fair play to England and fair play to France. I've never received a trophy in such a bizarre situation [after being handed the cup on the Murrayfield pitch]. It's strange. In some ways it's better than last year."
England head coach Stuart Lancaster: "I'm gutted really. It was one of the most courageous performances I've seen from a team. It was an unbelievable game of rugby."
Ireland head coach Joe Schmidt: "It was tumultuous. Exhausting. I spare a thought for England, they were superb today and probably deserved a share of the spoils."
Media playback is not supported on this device
England scrum-half Ben Youngs: "I don't really know what to say. I'm devastated. Congratulations to Ireland. We're devastated. We gave it a crack, but you can't let them get back in the game."
Ireland's two-try scorer Sean O'Brien: "We knew what we had to do at half-time and we executed it very well. It was important we expressed ourselves. We had to win the game first and foremost and we stuck to our guns and got the result."
Wales head coach Warren Gatland: "We knew if we scored a couple of tries to get ahead of Italy we would break their spirit. It was a great second-half performance."
Former England hooker Brian Moore: "England will feel desolate. There is very little to choose between the top three teams on any given day."
Former Scotland full-back Gavin Hastings: "I am massively, massively disappointed by Scotland. I expected them to come out and put on a performance. But they have laid down and that is very sad to see."


US presidential hopeful Donald Trump has vowed to pursue an "America First" foreign policy, saying many nations, including allies, "ripped off" the US.

The frontrunner for the Republican nomination for the November election was speaking to the New York Times.
Mr Trump said he would consider pulling out troops from Japan and South Korea if they did not pay the US more.
He said he might stop buying oil from Saudi Arabia if it did not send troops to fight so-called Islamic State.
Mr Trump insisted he was "not isolationist" but "America First".
He said: "We have been disrespected, mocked, and ripped off for many, many years by people that were smarter, shrewder, tougher.
"We were the big bully, but we were not smartly led. And we were the big bully who was the big, stupid bully and we were systematically ripped off by everybody."
The thrust of Mr Trump's interview concerned the economic cost of US foreign policy.
Mr Trump cited the US debt - "soon to be $21tn" (Â£14.8tn) - and linked it to the fact the US "defended the world".
"No matter who it is, we defend everybody. When in doubt, come to the United States. We'll defend you. In some cases free of charge."
He said that China had rebuilt itself from money that has "drained out of the United States".
"They've done it through monetary manipulation, by devaluations. And very sophisticated. I mean, they're grand chess players at devaluation."
He added: "I like China very much, I like Chinese people. I respect the Chinese leaders, but you know China's been taking advantage of us for many, many years and we can't allow it to go on."
Mr Trump also cited Japan, South Korea, and nations in the Middle East as not paying their way.
Mr Trump said the US was "not being properly reimbursed" for protecting Saudi Arabia.
"Without us, Saudi Arabia wouldn't exist for very long. It would be, you know, a catastrophic failure without our protection.
"They're a money machine... and yet they don't reimburse us the way we should be reimbursed."
He also cited Nato, saying it was "obsolete" as the main international threat now was terrorism.
"Nato is something that at the time was excellent. Today, it has to be changed."
The US, he added, bore "far too much of the cost of Nato".
Mr Trump expressed a similar view about the US funding of the United Nations.
He said: "We get nothing out of the United Nations. They don't respect us, they don't do what we want, and yet we fund them disproportionately again."
Mr Trump also referred to the criticism he had received for calling Brussels a "hellhole waiting to explode" but said that, after the deadly attacks on Tuesday, he had been proved right.
He spoke of the arrest before the attacks of key suspect Salah Abdeslam.
Mr Trump, who has said he supports the use of some methods of torture in some cases, said that if Belgian authorities had "immediately subjected him to very serious interrogation - very, very serious - you might have stopped the bombing".
Mr Trump also touched on Mexico, having previously accused Mexican immigrants in the United States of being criminals and rapists, and vowing to build a wall on the border.
He said US jobs were being lost to Mexico "and it has to be stopped".
Many Mexicans have been outraged by Mr Trump's stance. On Saturday, an effigy of him was burned in Mexico City on Saturday in a twist on the Easter "Burning of Judas" tradition.


Staff numbers at a water bottling plant in Pembrokeshire are set to be doubled after a major investment.

Princes Gate, which produces and bottles organic spring water in Narberth, is investing £5.5m in the hope of expanding its operation.
It aims to create 25 new jobs over the next three years - bringing the total number it employs to 50.
The investment is supported by £250,000 business finance from the Welsh government.
The company will also introduce a new bottling line, capable of producing 37,000 bottles an hour.


Judges at the Appeal Court in Belfast have questioned whether recently published abortion guidelines from the Department of Health need to be examined to establish whether they clarify the law sufficiently.

It is the second day of an appeal against a High Court decision which found that Northern Ireland's abortion law is "incompatible" with human rights legislation.
The Lord Chief Justice asked if a lack of clarity surrounding the law caused a chill factor among doctors.
The appeal began on Monday and is being taken by the Department of Justice and Northern Ireland Attorney General John Larkin.
In December, a judge ruled the law did not comply with the European Convention on Human Rights in cases of fatal foetal abnormality or sexual crime.
That case was brought by the Northern Ireland Human Rights Commission.
However, the justice department believes the ruling by the High Court could lead to a widening of the abortion law.
The current abortion legislation differs from the rest of the UK as the Abortion Act 1967 was never extended to Northern Ireland.
Currently, a termination is only permitted in Northern Ireland if a woman's life is at risk, or if there is a risk of permanent and serious damage to her mental or physical health.
Earlier on Tuesday, the Health Minister Michelle O'Neill confirmed that the working group proposed to deal with the issue of abortion in Northern Ireland has not been officially established.
It was due to be set up in February.
Ms O'Neill told MLAs that the terms of reference for the group had been drafted but "have not been formally signed off".
She said this meant consequently that the group has not yet met.


The prospects for this year's grouse shooting season, which has just begun, are said to be "unusually favourable".

Landowners and gamekeepers across Scotland are reporting that the mild spring and warm summer have resulted in high grouse numbers.
But conservationists are using the start of the season to highlight the illegal persecution of birds of prey.
They have claimed sporting estates and politicians could do more to end the practice.
Tim Baynes of the landowners' organisation, Scottish Land and Estates, said: "We got a nice dry spring, then no horrible weather through the hatching period in May.
"Everyone is optimistic for a very good season."
David Miller
Depending on your view point, the start of the grouse shooting season may or may not be described as "glorious".
For Scotland's sporting estates and the gamekeepers they employ, the twelfth of August is one of the most important dates in the calendar.
They use the occasion to hammer home the case for grouse shooting, citing benefits for the rural economy and wildlife.
But their critics, and there are many, will not find the "Glorious Twelfth" a cause for celebration.
Instead, their focus will be on the illegal killing of birds of prey, for whom the red grouse is a valuable source of food.
Landowners and gamekeepers' leaders condemn raptor persecution.
But the killing continues and so does the controversy.
The Scottish Gamekeepers' Association (SGA) is highlighting research which suggests the sport is worth around Â£32 million to the rural economy.
SGA chairman Alex Hogg said: "A good season for sporting visitors helps the small rural communities, the tourism businesses, shops and retailers that require the cash injection as we head into the less seasonal months."
The grouse shooting season is beginning against a backdrop of ongoing controversy over the poisoning, shooting and trapping of birds of prey.
Scottish Land and Estates and the Scottish Gamekeepers' Association have repeatedly condemned raptor persecution.
But environmental groups say they must do more to stamp out the practice.
Meanwhile, the high street retailer, Marks and Spencer, has said it will not stock grouse this year because it can't secure sufficient numbers of what it calls "responsibly sourced and third party accredited" red grouse.
The Lush cosmetics chain has been inviting its customers at stores across Britain to sign a postcard to the Queen, calling for action to protect the hen harrier.
And the League Against Cruel Sports has called on the tourism agency VisitScotland to end the promotion of Scotland as a destination for driven grouse shooting.
In response, VisitScotland said it must remain impartial and could not "discriminate" against one section of the tourism industry.
The environment minister, Paul Wheelhouse, told BBC Scotland News: "The model of a shooting estate is changing in the 21st century and there is considerable potential for closer alignment of conservation and sporting interests than in the past.
"This is why we support the independently accredited Wildlife Estates Scotland scheme which, I hope, can in future signpost those intending to participate in a shoot to the growing number of estates that manage their grouse shooting or other sporting rights in harmony with wildlife, such as raptors - and steer away from the small number of operators who continue to harm our wildlife."
The Scottish government is introducing a range of measures designed to tackle wildlife crime, including restrictions on the use of general licences where wildlife crime is suspected.
It has said it will take further action if required.


One of the key issues facing Antonio Guterres, the UN's newly installed secretary-general, will be to address critical failures in African peacekeeping operations.

With this is mind, he will surely be asking himself whether the vast organisation he is now leading needs to chart a different course.
The UN spends close to $8bn (Â£6.5bn) every year on peacekeeping around the world, with the bulk going to missions in Africa.
A new report by the Geneva-based research group Small Arms Survey has accused the UN's mission in South Sudan (Unmiss) of lacking neutrality by giving arms to rebels in the town of Bentiu in 2013.
It blames Unmiss for underreporting arms confiscated from fleeing soldiers and handing over the weapons to soldiers of the Sudan People's Liberation Movement-in-Opposition (SPLM-IO) on more than one occasion.
The report also claims that shortly after this transfer of arms, the rebels went on to carry out a massacre of civilians.
The operations of the UN's mission in South Sudan came into sharp focus after embarrassing revelations that its troops failed to protect civilians following clashes between government forces and former rebels in July 2016.
A damning internal investigation found that its peacekeeping mission in the capital, Juba had failed to achieve one of its core mandates, namely "to protect civilians under threat of physical violence [â€¦] with specific protection for women and children".
It described the troops' response as chaotic and ineffective.
Eyewitnesses said women and girls were raped near UN compounds with no action from peacekeepers.
Not far away, foreign aid workers suffered similar sexual violence at their residence. Their case gained much international condemnation, but it is dwarfed by the scale of the atrocities South Sudanese civilians have long experienced.
In a recent report to the Security Council, the outgoing Secretary General Ban Ki-moon offered little hope.
"There is a very real risk of mass atrocities being committed in South Sudan," he said.
"[...] The secretariat will continue to make every effort to implement the mandated task of protecting civilians through the use of 'all necessary means'.
"[But] it must be clearly understood that United Nations peacekeeping operations do not have the appropriate reach, manpower or capabilities to stop mass atrocities," his statement said.
In February, gunmen killed 30 internally displaced people and wounded more than 120 others within one of the UN's designated Protection of Civilian compounds in the north-western South Sudanese town of Malakal.
The irony of the facility failing to live up to its name was not lost on the mission's critics.
The UN later accepted responsibility for its failure to prevent the bloodbath.
In the Central African Republic (CAR), the UN mission (Minusca) has also been accused of inaction when, for example, more than 75 people including civilians were killed in the north during an outbreak of violence in September 2016.
The rights group, Amnesty International, reflected on this case, saying Minusca was poorly trained and "lacks the resources it needs to adequately protect civilians."
Jean-Serge Bokassa, the Interior Minister of CAR, accused the peacekeepers of colluding with armed militias.
"What is the role of the Pakistani contingent in Kaga-Bandoro?" he asked. "Their collusion with armed groups has gone too long."
A week later, four people died in the capital Bangui during anti-UN protests.
In the neighbouring Democratic Republic of Congo, similar disdain for the UN and its peacekeeping mission Monusco (which replaced the dysfunctional Monuc), has led to violent demonstrations and attacks by civilians in the past.
Most of the anti-UN protests have taken place in the eastern region of Kivu, where armed groups continue to commit massacres, especially in the Beni region.
Peacekeepers have often been referred to as tourists because they are associated with helicopters and 4x4 vehicles.
Charles Bambara, the spokesman for Monusco, says the task of the mission is so enormous that it's easy to underestimate progress being made.
"This country was divided into three: one armed group was controlling Goma area, another one controlling Kisangani and another one controlling the capital city and the west of the country," he says.
"So the aim when this mission was established was to reunite the country. This has now been done, with the support of the DRC armed forces. We need the support of the international community.
"This is a very difficult mission. There are probably 40 or 50 armed groups present in this country, which is as big as Western Europe, so we cannot be everywhere and that's why we're targeting these groups one after the other."
One notorious and repeated blight on the UN peacekeeping scorecard has been that of the discipline - or the lack of it - of troops.
A UN inquiry has named 41 peacekeepers in relation to alleged sexual abuse and exploitation in the Central African Republic between 2014 and 2015.
Women and even minors were reportedly abused in exchange for food and clothing. The UN has taken very little action against the individual soldiers.
Prosecutors in Paris said this week that charges would not be brought against six French peacekeepers following a criminal investigation into similar allegations.
Each country is responsible for charging its implicated troops but guilty verdicts might not be in a nation's best interests as that would taint its reputation in peacekeeping - although these track records are not officially considered when selecting which countries contribute to the missions.
The UN undersecretary for peacekeeping operations, Herve Ladsous, recently denied there was a crisis in UN peacekeeping.
"Some operations are working very well. For instance, we are a few months away from an end to the operations in Cote d'Ivoire and Liberia. Their success enables us to withdraw," he said.
"However, some operations are working less well, frequently because of factors linked to the local political situation and local players, rather than to the shortcomings of our operations themselves."
For effective peacekeeping, a former commander of a past UN mission, who asked not to be named, suggests:
The ex-UN insider says there needs to be more effort placed on ensuring urgency in political processes.
Otherwise, local armed groups will begin to threaten the rule of law when they discover that the UN troops only bark without biting, he says.
But analysts say the list of shortcomings of the UN operations might not necessarily mean that peacekeeping, as a concept, is a failure.
"It has to be better thought, better planned and better implemented and made more fit for purpose," says Gustavo de Carvalho, a senior researcher at the Institute for Security Studies (ISS Africa).
"If you are clearer in your mandate and how you engage with the local population, it becomes a far more honest interaction between foreign and local actors."
Mr de Carvalho proposes the following steps towards maintaining or winning back the confidence of local populations:
In the end, he says, putting boots on the ground is only one way to staunch the wounds of conflict.
"Peacekeeping is a short-term tool so we need to think of how to link this to long-term peace-building process."


Chinese stocks have plunged for a second day after worries over China's slowing growth triggered a global sell-off.

The Shanghai Composite, China's main stock exchange, fell 7.6% on Tuesday - after losing 8.5% on what state media have called China's "Black Monday".
It was the worst fall since 2007 and caused sharp drops in markets in the US and Europe
Tokyo's Nikkei index had a volatile day, closing 4% lower.
Live coverage of global markets
The Shanghai index ended the day 245 points lower at 2,964.97.
After decades of rapid growth, China is slowing down, and investors globally are worried that firms and countries which rely on high demand from China - the world's second largest economy and the second largest importer of both goods and commercial services - will be affected.
Read more: The six Cs of the China stock slump
The stocks fall in facial expressions
Some investors had hoped that the Chinese government might make a dramatic intervention to help.
But after two months of attempting and failing to shore up the markets at a cost of hundreds of billions of dollars in state funds, even Beijing now seems to be thinking hard about what stock prices are sustainable in the long term.
For a government whose legitimacy rests on economic competence, and which had hoped that a rising stock market would help ease the problems of a wider economic slowdown, this financial crisis still carries real political dangers.
Andrew Walker: How the China share slump affects the rest of the world
Karishma Vaswani: China counts cost of Black Monday
Robert Peston: Will Chinaâ€™s slowdown make us poorer?
Duncan Weldon: China share falls - why it's not 2008
Chinese shares had experienced a year-long rally - mainly fuelled by investors borrowing money to buy shares - which came to an end in June.
The Chinese government then intervened in financial markets, to try to maintain momentum in the economy.
Two weeks ago the central bank devalued the currency, the yuan - this raised fresh concerns that China's economy could be in worse shape than previously thought.
A cheaper currency lowers the price of China's exports, making them more attractive to global firms.
Elsewhere in Asia and Australia on Tuesday, markets beat expectations, opening lower but then returning back to positive territory:
The dollar remained weak at 119.15 yen, up from a seven month low of 118.51 yen in New York on Monday.
Commodity prices also recovered after Monday's falls, although oil remains under pressure because of a global oversupply.
Overnight, the Europe and the US saw dramatic falls, but are expected to show some signs of recovery when they open on Tuesday.


Manchester City's title hopes suffered a setback as they drew at struggling Norwich to move nine points behind leaders Leicester with nine games left.

Canaries keeper John Ruddy kept out two Sergio Aguero efforts as the home side resolutely kept the visitors at bay.
However, it was Norwich who came closest to a goal when a 25-yard Patrick Bamford shot hit the crossbar.
The home side might even have snatched a late winner but Graham Dorrans put a shot wide when well placed.
Relive Norwich's goalless draw with Man City
Manchester City have now won only two of their past 11 away games in the league, and Manuel Pellegrini's side failed to respond to his warning they had no "margin for error" in the title race.
Pellegrini opted for a 4-4-2 formation, with Wilfried Bony partnering Aguero in attack, but despite their dominance the visitors rarely looked dangerous and failed to muster a shot on target in the second half.
Bony was a peripheral figure and it was little surprise when he was replaced just before the hour mark by Raheem Sterling, though the winger's introduction failed to lift the away side.
The worry for Pellegrini, who will be replaced in the summer by Bayern Munich boss Pep Guardiola, will be the lack of creativity, intensity and urgency from his side.
"Me and [Norwich goalkeeper] John Ruddy could have had the afternoon off to be honest," said visiting keeper Joe Hart. "We weren't good enough to win the game."
Hart and his team-mates will be looking over their shoulders in the race for Champions League football, with only a two-point gap between them and fifth-placed West Ham.
Norwich remain in the bottom three after winning only their second point from their past 10 league games.
But, if they can continue to defend in the same way and add goals to this sort of performance, they will believe they can avoid relegation.
"It is a big point and sends a message out to the teams around us and maybe dents them again," said Norwich defender Russell Martin.
Canaries boss Alex Neil has rarely had cause to question his side's desire, and his players again put in a performance full of effort and commitment - running 5km more than their opponents.
The plan might have been to frustrate their visitors and hope to catch them on the break, but scoring goals remains an issue with just three in their past seven games.
Neil hoped giving Bamford his first Premier League start might solve the problem but though the on-loan Chelsea forward went closest to scoring, Norwich did not manage a shot on target.
Manchester City manager Manuel Pellegrini: "We are disappointed. We tried to be aggressive with and without the ball. We had a good attitude but we could not create space.
"Of course we should create more in the last third. We were static up front. Every time that you drop points it is harder but you must continue thinking in a positive way. We must always try to win the title while we mathematically can."
Media playback is not supported on this device
Norwich City boss Alex Neil: "We will see at the end of the season how significant that point was.
"We had much better decision-making. Last time Norwich got relegated they were five points above the relegation zone with seven games to play so there's no reason why we can't catch some of those above us."
Media playback is not supported on this device
Former Norwich striker Chris Sutton on BBC Radio 5 live: "This is the end for Manchester City now, they are not going to win the title. Absolutely done. They have been like it all season. They just haven't shown enough urgency or real effort to win."
Manchester City will take a 3-1 lead into the home leg of their Champions League last-16 tie against Dynamo Kiev on Tuesday (19:45 GMT). Norwich's fight for survival sees them visit West Brom on Saturday, 19 March (15:00 GMT) in their next game.


Northern Ireland Water and trade unions are to hold further talks later to resolve a pensions dispute.

Nipsa, Unite and GMB members voted last month for a work-to-rule and withdrawal of on-call services and overtime.
Water supply to about 10,000 customers in counties Fermanagh and Tyrone was disrupted over the weekend.
The company said one of five pumps at its Enniskillen treatment plant broke down, and industrial action meant repairs were delayed.
The disruption continued to affect hundreds of customers on Monday.
Agreement was reached before Christmas to provide some emergency cover, but following talks facilitated by the Labour Relations Agency last week, unions rejected an offer made by management on Friday.
NI Water made proposals for changes to its pension scheme last July.
Unions say increased pension contributions could cost members up to Â£100 a month, and they want this to be offset by an increase in salaries.
They also want pension changes to be delayed for a year until April 2016.
NI Water say increased contributions for most staff would be much less than the Â£100 claimed by the union, and any pay deal would have to include changes to some working practices, including longer working days for some staff.


A museum celebrating the life and work of British artist William Heath Robinson is set to open.

The Heath Robinson Museum will provide a permanent home in Pinner, north-west London, for the largest collection of the artist's work.
It is the first purpose-built museum to open in the capital in more than 40 years.
The museum is being opened by the William Heath Robinson Trust and supported by Â£1.3m of Lottery funding.
A programme of special exhibitions will go on display from 15 October.
Born in 1872, Heath Robinson trained at the Islington School of Art and moved to Pinner in 1908.
His drawings of complicated inventions saw his name enter the lexicon in 1912 as a synonym for absurdly ingenious devices.
Wallace and Gromit creator Nick Park and Olympic Cauldron designer Thomas Heatherwick are among those to have cited him as an influence.
The artist died in September 1944, aged 72.
Last year, a collection of 410 drawings and paintings which included many of his best-known World War One and Two cartoons were saved for the nation and acquired by the trust.


Coventry City's blistering start ended Sheffield United's slim chance of achieving a League One play-off place.

The Sky Blues led after Adam Armstrong's effort was deflected in by Marc-Antoine Fortune.
The Blades were 2-0 down after only eight minutes when Andy Rose poked in from a George Thomas through ball.
Billy Sharp's penalty gave the visitors hope, but Ruben Lameiras made sure of the points for the home side when he fired in from a Jodi Jones pass.
Coventry's first three-goal performance in 14 games helped them leapfrog the Blades into ninth, Tony Mowbray's men having now won three of their last four games.
After a late run of three wins from five matches had put them on the brink of the top six, the Blades can now no longer make the play-offs,
Sky Blues boss Tony Mowbray told BBC Coventry and Warwickshire:
"It was fitting for the season we have had at home, a good way to finish off.
"I told them to relax and play with a smile on their face. We started the game very brightly and it was great to finish as we did.
"It was good to score some goals, which has been our problem for the second half of the season, and good that we did it for the fans."


The taxi-hailing app operated in London by the US firm Uber does not break the law, the High Court has found.

The court had been asked to decide whether the company's smartphones were considered meters, which are outlawed for private hire vehicles.
The phones use GPS and external servers to calculate the cost of a journey.
Transport for London said taking the case to court had been "in the public interest".
The app-based company allows users to order cars via their smartphones, which often arrive within minutes and can cost a fraction of the price of a black cab.
What will the High Court decision mean for Uber?
Mr Justice Ouseley declared that taximeters do not operate in the same way as the app as they do not depend on GPS signals or include the app's other new-tech characteristics to calculate fares.
TfL and Uber had both argued at a one-day hearing earlier in October that the app was not a meter, and both organisations greeted the decision as a victory.
An Uber spokesman said: "This was not a marginal call; it is quite emphatic. In fact, it is contemptuous of the case brought before it."
Transport for London also welcomed the ruling, saying there had been "significant public interest in establishing legal certainty in the matter".
The Licensed Taxi Drivers' Association (LTDA), which represents many of the 25,000 licensed taxi drivers in London, asked the judge to rule it was a meter and ban its use.
LTDA chairman Richard Massett said: "We certainly are going to an appeal.
"It's a fact that the smartphone acts in exactly the same way as a taximeter. It calculates the fare by means of time taken and distance covered - and it's doing exactly the same job.
"Private hire legislation specifically precludes private hire from using a meter - and that's exactly what it is."
The Licensed Private Hire Car Association (LPHCA) backed the LTDA and said the app was "an attempt to circumvent the statutory prohibition" on minicabs using meters.
This is not the end of this story - I think it is only the beginning.
As well as probable legal challenges to the High Court taximeter ruling, there are big changes to regulation being proposed by the mayor.
Among those are a five-minute wait between booking a taxi via an app and the pick-up - and a ban on apps showing which cars are immediately available. That would seriously curtail how Uber currently operates.
A huge lobbying battle is now under way. Expect more protests from black cab drivers.
The policy-makers are scrambling to keep up with this new technology - it has tied them in knots.
There are also differing political opinions on the Uber app - the business secretary said in July he and the government welcomed "disruptive technology" - and that clashes with what the mayor is trying to achieve with his private-hire proposals.
Black cab drivers argue that the app poses a risk to public safety and customers being overcharged, with no opportunity to challenge fares before the money is automatically taken out of their bank accounts.
A spokesman for London Mayor Boris Johnson said: "The mayor is a strong supporter of new technology and he recognises that innovation is embraced by Londoners."
However, he acknowledged "huge challenges" for the taxi and private hire trades, and "legitimate concerns" over vehicle emissions and congestion.
He pointed out that TfL was carrying out a consultation on how to regulate the industry.
Uber's Jo Bertram said: "Now the High Court has ruled in favour of new technology, we hope TfL will think again on their bureaucratic proposals for apps like Uber.
"Compulsory five-minute waits and banning ride-sharing would be bad for riders and drivers. These plans make no sense. That's why 130,000 people have already signed our petition against these proposals."


Rory McIlroy endured a difficult third day to fall out of contention at the BMW Championship in Denver.

The Northern Irishman's worst round of the tournament - a 72 - leaves him on four under and nine shots off the lead, held by American Billy Horschel.
American Ryan Palmer retains second after a 67 took him to 10 under.
German Martin Kaymer propelled himself into the running with a 64 but overnight leader Sergio Garcia (Spain) fell away after a disappointing 72.
The top 70 players on the FedEx Cup points list after the Deutsche Bank Championship qualified for this week's event, with only the top 30 advancing to the finale, which begins on Thursday.
McIlroy, who is second in the points list, got off to a bad start with a bogey at the third and, despite birdies at the fourth, sixth and seventh, a dire triple-bogie at the 12th severely damaged his standing.
"Glad everybody enjoyed my four-putt today," he tweeted. "Always tomorrow to get a few shots back and get up that leaderboard!"
It was the same for Garcia, whose putting let him down as he bogeyed the seventh, eighth and 14th.
However, there were no such concerns for Horschel, who carded a bogey-free round and capped his day with a superb, long putt on the last to give him his seventh birdie of the day and a commanding lead.
"It's going to be a fun day tomorrow," he said afterwards. "Obviously having a chance to win a golf tournament on the PGA Tour, especially during the FedEx Cup play-offs, can go a long way.
"We'll see what happens. If I can just keep doing what I'm doing and maybe I'll be holding a trophy on Sunday."
Palmer, who needs a high finish to get into the FedEx Cup top 30 and reach next week's Tour Championship in Atlanta, was less consistent with six birdies and three bogeys, while Bubba Watson was in typically-aggressive mood to card a bogey-free 66 and move to eight under and joint third with Kaymer.
American Morgan Hoffmann produced the round of the day with a career-low 62, which included nine birdies, to take him to four-under.
His compatriot Chris Kirk - who holds the overall FedEx Cup lead after two of the four play-off events - dropped two shots to move to one over.
American Keegan Bradley pulled out of the tournament before teeing off his third round on Saturday over a potential rules infraction regarding a drop taken in the opening round.
The 28-year-old, who was 11 strokes off the lead at the halfway stage, had lingering doubts over the legitimacy of a free drop taken in Thursday's round after his third shot at the par-four 18th had embedded in grass just above a bunker.
"I just feel withdrawing is the right thing to do to protect the field in the BMW Championship and the Tour Championship next week," said Bradley, whose withdrawal could cost him a place in next week's event in Atlanta.
Bradley's withdrawal comes after fellow American Phil Mickelson also announced he was pulling out of the tournament at the halfway stage in order to focus on the Ryder Cup, which takes place at Gleneagles in Scotland from 26-28 September.


Long-time residents joke that you need to live in Delungra for 30 years before you're truly considered a local, writes Katie Beck.

Formerly a bustling grain farming hub, it's now a typical northern New South Wales town with a bowling club, service station, hotel and post office.
But in 2015, Delungra was named Australia's lowest-earning postcode by the Australian Taxation Office, with a mean taxable income of just $21,691.
The town's 330 residents are bemused by this dubious honour. They say it doesn't reflect their experience of living in the town, where volunteerism is the norm and friendships run deep and long.
This is what locals say it's like to live in Australia's poorest town.
Jim, 79, has lived in Delungra all his life. He owned the town's service station for a number of years and has been active in keeping the post office open.
Delungra's post office has long been a gathering place for the town's residents. So it was a big blow when Australia Post announced it would be shutting the local branch due to cost.
The closure would have forced residents to travel over 30km to get their mail. Instead, locals came together to keep their post office open and to retain their postcode. The local branch is now staffed by 10 volunteers.
"The local council got together and put the word out," Jim says. "We got a good selection of volunteers and we've kept [the post office] open.
"It's very important, it gets the people from the country into the post office, we get to meet them and that way we get to know who's who."
Tim's family has been in Delungra for generations. His grandfather settled here in 1920 and Tim and his father have been farming cattle for 40 years. He says the monetary wealth of a town isn't what's important.
"It's not necessarily the wealth of a town or the wealth of people - you don't need a lot of money to live and to be happy. It's community spirit and that's what any community desperately needs. The smaller the community, the more people are going to put their hands up."
Locals may joke it takes 30 years to be truly accepted in Delungra, but Philippa says she was welcomed on her first day when she moved here with her family 10 years ago.
"They were so nice, everyone smiled and waved and went out of their way to talk to you because you were the newbies in town," she says. "I think its still the same way.  Everyone wants to help everyone."
She was surprised to see her town listed as the poorest in the nation.
"It's totally not, it's totally the opposite. I mean you look around and you see the beautiful houses. There's no bias, whether you've got multimillions or whether you've got two dollars in the bank. I couldn't imagine myself being anywhere else."
John's family has run businesses in Delungra for decades. His son finally closed the family-owned café a couple of years ago. He says the low mean income can be explained by the number of retirees in town, but says calling the town the lowest-earning in the country gives the wrong impression.
"I think there's worse places than this!" he says. "There'd be more people on the dole somewhere else then there are here. If you like a quiet life, I'd say come and live in Delungra.  It's as simple as that."
Harry moved to town about 25 years ago and is deeply involved in the community. He leads the Delungra District Development Council, which maintains town archives and organises volunteers, whom he says are integral to keeping the town running.
"We think that Delungra needs some tender, loving care, and we've got volunteers to do it," he says. "We mow lawns around the district, we maintain parks, volunteers built our Anzac gateway and memorial, they man the local garbage dump two days a week, we man the post office.
"Delungra is quiet, the air is fresh, the birds sing, the sun shines, and it's just a relaxed way of life and I couldn't imagine living anywhere else. I think whoever says this is a poor community, should get on the train and come visit because being here is a different story."
Lorna lives an hour away, but serves as secretary of the women's bowls club, the development council and the Australia Day committee in Delungra. In contrast to her city life, where she did not know her neighbours, she was quickly accepted when she started coming to Delungra.
"It's not a poor town. We haven't got the facilities but ... the lifestyle, it's quiet and relaxed. Here you know your neighbours, everybody knows everybody [and] if someone's in trouble, someone will come and help."
Robert says: "When I was a kid, this was a thriving town. They had barley stacks, they had shops, they had pubs and clubs, everything. Everybody's making a dollar. People need to realise that when people retire, if people don't take their job over [then] things just sort of decline. But the town's still here and you can't take Delungra away from Delungra."
"It's fantastic, that's my opinion. I love the place. It's the peace and the company of the people. I've known these people since I was a kid. I went to Sydney, I've been overseas and I always come back here. When they take me from here I'll probably be in a box."


A Jordanian official has said a ban has been lifted on a concert by a Lebanese band that tackles taboos in the Arab world and has a gay lead singer.

Mashrou' Leila was told earlier this week that it could not perform in Amman on Friday evening because its songs "contradicted" religious beliefs.
But late on Thursday, Amman's governor said authorities no longer objected.
Mashrou' Leila welcomed the decision, but complained that it had been told too late for the concert to take place.
The ban had sparked criticism of Jordan, one of the region's most liberal countries.
In a post on their Facebook page, the five members of Mashrou' Leila said they wanted to thank artists, musicians, intellectuals and civil society activists from Jordan and elsewhere for "standing with us".
They said had been "shocked" when Jordanian interior ministry officials and religious figures stated that their music contradicted Islam, Christianity, and the values of Jordanian society.
"What we see here is superficial cultural criticism, simple, reductive, and basing itself on the extraction of certain words from their structural context within their songs, and then from their figurative framework as metaphors," they added.
"The critic then offers a simplistic analysis of the song, stripping the writer from his freedom to use metaphor within the texts, to conclude that the writer is a satanist."
The band members said they wanted to "congratulate" Amman governor Khalid Abu Zeid on sending them a letter of approval from the interior ministry, but regretted it came "too late" for the concert to go ahead.


Security researchers are considering buying undetected software security vulnerabilities from a notorious group of hackers.

The Shadow Brokers group has previously leaked exploits allegedly stolen from the US National Security Agency (NSA), and is offering more for sale.
Some researchers want to buy the next batch of hacking tools, and help fix them before cyber-criminals strike.
But critics argue that the Shadow Brokers should not be funded.
Security holes in operating systems such as Windows 10, Android and Apple's iOS can give governments and criminals a backdoor in to their targets' devices.
The Shadow Brokers group wants to sell a new batch of such exploits in June, for about $22,000 (Â£17,000) in virtual currency.
On Tuesday, two security researchers set up a crowd-funding campaign to buy access to the exploits, so that they could be fixed instead.
"We have seen credible threats from the Shadow Brokers," said Matthew Hickey from the cyber-security firm Hacker House, who set up the crowd-funding campaign.
"They have come good on previous promises to release tools, and one of them was involved in the spread of WannaCry ransomware.
"When somebody is releasing tools of that calibre and says they have more to release, I'm sure people would be happy to pay $20,000 to prevent them getting out."
However, the idea has divided the cyber-security community.
"There's a 50-50 split on whether it is a good idea and whether it would encourage Shadow Brokers to continue their activities," Mr Hickey told the BBC.
Others were more outspoken: "Individuals and corps funding criminals is insane," said security researcher Kevin Beaumont.
"Here's an idea - [the NSA] should inform all vendors of bugs now since they're being traded on black market," he tweeted.
According to the Washington Post, the NSA informed Microsoft about some of the hacking tools that were stolen.
But Mr Hickey argued more needed to be done.
"If these tools have originated from the NSA, they should make a statement publicly, so that people can actively defend themselves from these threats," he told the BBC.
The Shadow Brokers group has not detailed what buyers would get if they paid the $22,000 bounty, and has offered no guarantee that buyers would be rewarded at all.
"If you caring about loosing $20k+ Euro then not being for you... playing 'the game' is involving risks [sic]," the group said in a blog post.
It is demanding payment in the form of 100 ZEC - a crypto-currency called Zcash that is designed to be untraceable.
Mr Hickey admitted the crowd-funding may be fruitless in the end, but added that he was happy to give people the option.
"If we raise the money and go ahead and buy the tools, it will stop them getting into the hands of criminals," he said.


Drilling companies suggest trillions of cubic feet of shale gas may be recoverable from underneath parts of the UK through a process known as "fracking".

Hydraulic fracturing, or fracking, is a technique designed to recover gas and oil from shale rock. But how does it work and why is it controversial?
Fracking is the process of drilling down into the earth before a high-pressure water mixture is directed at the rock to release the gas inside.
Water, sand and chemicals are injected into the rock at high pressure which allows the gas to flow out to the head of the well.
The process can be carried out vertically or, more commonly, by drilling horizontally to the rock layer and can create new pathways to release gas or can be used to extend existing channels.
The term fracking refers to how the rock is fractured apart by the high pressure mixture.
No. Drilling for shale gas is only at an exploratory phase in the UK.
However, reserves of shale gas have been identified across large swathes of the UK, particularly in northern England.
More than 100 licences have been awarded by the government to firms in the UK, allowing them to pursue a range of oil and gas exploration activities in certain areas.
But before firms can begin fracking they must also receive planning permission from the relevant local council.
The government has said it would make a final decision on whether to allow drilling at two sites in Lancashire, after the application was rejected by Lancashire County Council in June. An appeal will be heard next year.
Applications have also been submitted in Yorkshire and Nottinghamshire.
Downing Street has said shale gas planning applications in England are to be fast-tracked to crack down on councils that delay decisions.
However, Labour has called for a moratorium on fracking "until we can be sure it is safe".
Governments in Scotland, Wales and Northern Ireland have all said they will oppose fracking - until further research is completed into its environmental impact.
In 2011, energy company Cuadrilla suspended test fracking operations near Blackpool, in Lancashire, after two earthquakes of 1.5 and 2.2 magnitude hit the area
A subsequent study found it was "highly probable" that shale gas test drilling triggered the tremors.
A government-appointed panel said there could be more tremors as a result of fracking, but they will be too small to do structural damage above ground.
It recommended greater monitoring and that operators should observe a "traffic light" regime, with tremors of magnitude 0.5 or above triggering a "red light" and an immediate halt.
Fracking allows drilling firms to access difficult-to-reach resources of oil and gas.
In the US it has significantly boosted domestic oil production and driven down gas prices. It is estimated to have offered gas security to the US and Canada for about 100 years, and has presented an opportunity to generate electricity at half the CO2 emissions of coal.
The industry suggests fracking of shale gas could contribute significantly to the UK's future energy needs.
The Task Force on Shale Gas, an industry-funded body, has said the UK needs to start fracking to establish the possible economic impact of shale gas - saying it could create thousands of jobs.
The extensive use of fracking in the US, where it has revolutionised the energy industry, has prompted environmental concerns.
Fracking uses huge amounts of water, which must be transported to the fracking site, at significant environmental cost.
Environmentalists say potentially carcinogenic chemicals used may escape and contaminate groundwater around the fracking site. The industry suggests pollution incidents are the results of bad practice, rather than an inherently risky technique.
There are also worries that the fracking process can cause small earth tremors.
Campaigners say that fracking is simply distracting energy firms and governments from investing in renewable sources of energy, and encouraging continued reliance on fossil fuels.
"Shale gas is not the solution to the UK's energy challenges," said Friends of the Earth energy campaigner Tony Bosworth. "We need a 21st century energy revolution based on efficiency and renewables, not more fossil fuels that will add to climate change."
Following the Paris climate change deal, Friends of the Earth chief executive Craig Bennett said Mr Cameron must "end Britain's scandalous support for fossil fuels, including fracking".
The government believes shale gas has the potential to provide the UK with greater energy security, growth and jobs.
Prime Minister David Cameron has repeatedly spoken of his support for fracking, saying it could support tens of thousand of UK jobs and reduce bills.
"I want us to get on board this change that is doing so much good and bringing so much benefit to North America. I want us to benefit from it here as well," he has previously said.
In January, MPs overwhelmingly rejected an outright ban on fracking but ministers did pledge an "outright ban" on fracking in national parks.
However, in December MPs voted to allow fracking at 1,200m below national parks, Areas of Outstanding National Beauty, the Norfolk and Suffolk Broads and World Heritage Sites.
Critics, including Labour and Greenpeace, accused the government of a U-turn.


Bournemouth look certain to reach the top flight for the first time in their 125-year history after Monday's 3-0 win over Bolton all but completed a remarkable rise from football's abyss to the top of the game.

The seaside club, whose 11,700-capacity Goldsands Stadium will be the smallest in Premier League history, began 2008-09 on minus-17 points in League Two because of administration and now are set to celebrate their place in football's top tier.
Chairman Jeff Mostyn said promotion for a club who were 24 hours from liquidation in 2008 "would be the greatest fairytale since Hans Christian Andersen wrote his last one", but is he right?
BBC Sport takes a look at some of the other clubs to have overcome the odds and whether their experiences give hope to the Cherries next season.
Club: Swindon Town
Population: Approximately 180,000
Average attendance in Premier League season: 15,274
Journey: Swindon Town's 4-3 Wembley win over Leicester in 1993 will go down as one of the most thrilling play-off finals, and marked the Robins' rise from the bottom.
The 1986 Fourth Division champions lost manager Lou Macari to West Ham in 1989. Former Tottenham midfielder Ossie Ardiles came in and, in his first season, they won promotion to the top flight as Second Division play-off winners, but there was a twist in the tale...
They were initially demoted to the Third Division for irregular payments, but partially won an appeal meaning they stayed in the second tier. Under the management of Glenn Hoddle, top-flight football was brought to the County Ground for the first time via the play-offs in 1993.
Outcome: Bournemouth fans will get little confidence from this - it was to be the club's only season in the top flight. With John Gorman replacing Hoddle, they won only five league matches and conceded a record 100 goals. They have since suffered financial problems and became the first former Premier League club to be relegated to the Football League's bottom division in 2006.
They said: "Coming back on the bus after Wembley, down the M4, the bridges were draped in flags, towels, anything that was red and white. You can never tire of remembering those days, they were wonderful times." - Former Swindon defender Paul Bodin
Club: Burnley
Population: Circa 81,000
Average attendance in Premier League this season: 19,133
Journey: Wade Elliott ensured himself legendary status in the claret half of east Lancashire when his 20-yard screamer won Burnley the 2009 play-off final against Sheffield United to end their 33-year top-flight exile.
Burnley spent most of their early history in England's top two divisions, but remained outside the top flight from 1976 to 2009. In 1987 - during a seven-year spell in the lowest tier of the Football League - they narrowly avoided relegation to the Conference.
Despite one of the lower budgets in the Championship, Burnley have won promotion twice to the Premier League in the last six years.
Outcome: They were unable to avoid immediate relegation in 2010, going down with two games to spare. They surprised many by returning to the top flight in 2014, this time under boss Sean Dyche. Top scorer Charlie Austin had been sold to QPR and Dyche had to work on a tight budget, heavily relying on free transfers and the loan market. They are currently bottom of the table and five points adrift of safety.
They said: "We had 36,000 supporters at Wembley, which is about half our population. When Manchester United play at home there are more people at Old Trafford than in the whole town of Burnley." - Ex-Burnley boss Owen Coyle in 2009
Club: Wigan
Population: Less than 90,000
Average attendance in their last season in Premier League in 2013: 19,375
Journey: Wigan Athletic did not come into existence until 1932, making them the youngest club to be promoted to the Premier League. They only joined the Football League in 1978. It began well enough but, in 1994, they finished fourth from bottom in the lowest tier and average crowds had dropped below 2,000.
The turning point came in 1995 when local businessman Dave Whelan, a self-made millionaire through his sportswear business, bought the club and immediately targeted the Premier League. The Latics, who moved to the JJB (now DW) Stadium, achieved that aim on the final day of the 2004-05 season with a 3-1 win over Reading.
Outcome: This is more like it, Cherries. Wigan took to Premier League life easily and spent much of their season challenging for European football as well as reaching the League Cup final. They stayed in the top flight for eight seasons, until relegation to the Championship in 2013, days after winning the FA Cup. The Latics are now on the verge of dropping into League One.
They said: "Any professional football club could have the dream of playing in the Premier League and winning a major trophy and Dave Whelan showed the way to do that. It is a great football story and I am sure it will inspire many generations to come." - Former Wigan boss Roberto Martinez
Club: Blackburn Rovers
Population: Circa 120,000
Average attendance in last season in Premier League in 2012: 22,500
Journey: Blackburn were far from top-flight novices prior to their promotion in 1992, winning the First Division in both 1912 and 1914 and enjoying spells in the top tier in the middle of the century. But, from 1966, the mill town experienced a 26-year exile from the elite.
A defeat in the 1989-90 Second Division play-off semi-finals was followed by the takeover of local steelworks owner and lifelong supporter Jack Walker, which started Rovers' transformation into Premier League champions. They appointed Liverpool legend Kenny Dalglish as manager and, in his first season, he took the club into the Premier League via a play-off win over Leicester.
Outcome: This will take some beating. Rovers finished fourth and second in their first two seasons in the top flight. They then made history by becoming the only town club ever to win the Premier League when they lifted the trophy on the final day of the season at Anfield.
Barring one season back in the Championship, they spent 20 years in the top flight, playing in the Champions League and winning a League Cup. However they were relegated in 2012 and are now ninth in the second tier.
They said: "No club our size will ever win the Premier League again. We had a bit of money but it was more to do with spirit, attitude and Kenny's ability to sign the right players. Local businessmen like Jack Walker couldn't compete with the money we are talking about these days."  - Former Blackburn Rovers striker Kevin Gallacher.
Club: Barnsley
Population: Just more than 90,000
Average attendance in Premier League season: 18,433
Journey: After 109 years, the Tykes gained entry to English football's elite division for the first time in 1997 with a 2-0 win over Bradford in the penultimate game of the season.
Because of their yellow away shirts, the Oakwell crowd were often known to sing "it's just like watching Brazil" in the stands as manager Danny Wilson secured his place in club folklore, building a team who played stylish, attacking football.
Outcome: Bournemouth fans look away now. Barnsley were immediately relegated after finishing 19th in the Premiership, five points adrift of safety. They entered administration in 2002 and were relegated from the Championship last season.
They said: "We've done it the right way, working hard and honestly and playing good football. These fans have seen a lot of hard times here, they deserve this." - Barnsley boss Danny Wilson
Club: Blackpool
Population: 140,000
Average attendance in last Premier League season: 15,780
Journey: Blackpool won the 2010 play-off final over Cardiff to clinch a top-flight place for the first time since 1971.
Achieved on the lowest wage bill in the Championship, it was witnessed by one of the smallest average attendances in the division and masterminded at a dilapidated training ground still in use since the days of the legendary Stanley Matthews.
Outcome: The Tangerines were relegated on the final day of the season, despite attacking performances that brought them much praise.
They almost won promotion again the next season but, since then, have had five managers, been relegated to League One for next season after only four league wins, and fans are protesting against owner Owen Oyston and son Karl.
They said: "It feels like we have landed on the moon without a space rocket or a helmet." - Striker Brett Ormerod.


The European Commission has fined three banks €485m (£413m) for rigging a key European benchmark rate.

The Euribor rate is used to calculate the value of many financial products worth billions of euros.
HSBC, JPMorgan and Credit Agricole illegally exchanged sensitive Euribor information to make a profit on those products, the Commission said.
JPMorgan and HSBC have denied wrongdoing, and says they may appeal against the decision.
Barclays, Deutsche Bank, RBS and Societe Generale all settled with the Commission over the case in 2013.
Commissioner Margrethe Vestager said: "Banks have to respect EU competition rules just like any other company operating in the single market."
The Commission fined JPMorgan Chase €337m, Credit Agricole €115m, and HSBC €34m.
It said the banks were part of a cartel relating to products used to manage the uncertainty of interest rate movements.
The investigation found that the cartel operated between September 2005 and May 2008.
Traders used chat rooms and instant messaging to tell each other desired or intended Euribor positions.
This distorted the pricing of financial products based on Euribor, the Commission said.
A JP Morgan spokeswoman said the banking giant had done nothing wrong.
"We have cooperated fully with the European Commission throughout its five year investigation," she said.
"We did not engage in any wrongdoing with respect to the Euribor benchmark. We will continue to vigorously defend our position against these allegations, including through possible appeals to the European courts."
An HSBC spokesman said: "We believe we did not participate in an anti-competitive cartel. We are reviewing the European Commission's decision and considering our legal options."
In 2013 the European Commission fined eight banks €1.7bn for euro and yen interest rate-rigging.
Two of the eight, whistleblowers Barclays and UBS, were excused their financial penalties.


Hijab, niqab, burka - there are lots of different kinds of coverings worn by Muslim women all over the world.

Some wear a headscarf to cover their head and hair, while others wear a burka or niqab, which also covers up their face.
Headscarves are seen as a sign of modesty, and a symbol of religious faith.
But how can you tell which one is which? Check out our guide to the various different types.
The word hijab describes the act of covering up generally but is often used to describe the headscarves worn by Muslim women. These scarves come in many styles and colours. The type most commonly worn in the West covers the head and neck but leaves the face clear.
The niqab is a veil for the face that leaves the area around the eyes clear. However, it may be worn with a separate eye veil. It is worn with an accompanying headscarf.
The burka is the most concealing of all Islamic veils. It is a one-piece veil that covers the face and body, often leaving just a mesh screen to see through.
The al-amira is a two-piece veil. It consists of a close fitting cap, usually made from cotton or polyester, and a tube-like scarf.
The shayla is a long, rectangular scarf popular in the Gulf region. It is wrapped around the head and tucked or pinned in place at the shoulders.
The khimar is a long, cape-like veil that hangs down to just above the waist. It covers the hair, neck and shoulders completely, but leaves the face clear.
The chador, worn by many Iranian women when outside the house, is a full-body cloak. It is often accompanied by a smaller headscarf underneath.


Hundreds of skeletons found under a Cambridge University college could help researchers map the effect of the Black Death on a medieval town's population.

More than 400 complete skeletons were discovered during work on St John's College between 2010 to 2012.
The remains, dating from the 13th to 15th Centuries, were burials from the Hospital of St John the Evangelist.
The four-year Â£1.2m study aims to learn more about the health of the urban poor during the epidemic.
About 1,000 parts from bodies were also discovered in what a St John's College spokesman described as "one of the largest medieval hospital burial grounds ever found in Britain".
The majority of the people buried on the site are poor townsfolk rather than clerics, and include men, women and some children.
The epidemic killed millions of people across Europe.
Researchers from a number of disciplines, including archaeology, history and genetics, will combine forces to "test directly the effects of the Black Death on a medieval town population before, during and after the epidemic".
The Hospital of St John the Evangelist was an Augustinian charitable establishment, providing care to members of the public between about 1200 and 1500.
The research is funded by the Wellcome Trust and St John's.


Padraig Amond scored his 30th goal of the season as Grimsby equalised twice to earn a draw at Guiseley.

Rob Atkinson gave the lowly hosts an early lead from a corner but Craig Disley headed in Ryan Jennings' cross to equalise for the promotion chasers.
Nicky Boshell restored Guiseley's lead with a rebound but Amond scored with a looping header from Evan Horwood's centre to earn the Mariners a point.
Grimsby stay third while Guiseley are now six points above the bottom four.
Grimsby Town manager Paul Hurst told BBC Radio Humberside:
Media playback is not supported on this device
"I think it was a missed opportunity for us as we had a lot of possession, missed some chances and conceded two poor goals.
"There were more chances to be had but that final pass, final bit of delivery we couldn't quite change advantage of.
"At 2-2 I still fancied us but I don't want to take anything away from Guiseley. I spoke well of them before and you can see they try and pass the ball."


The head of Welsh regional rugby says the new Pro14 could expand further after two South African sides were added to the tournament.

Media playback is not supported on this device
Southern Kings and Cheetahs have joined teams from Ireland, Italy, Scotland and Wales in the revamped Pro14.
Pro Rugby Wales chief Mark Davies believes the league must improve to match English and French tournaments.
"We can contemplate further geographical expansion, why wouldn't we?" said Davies.
"It's not on the back-burner. We can't afford to take our foot off the gas.
"Even when we're getting to the point of matching our first ambition of doubling our revenues, we're still behind our competition.
"We don't have the opportunity to coast, we have to keep pushing."
Davies is head of the Pro Rugby Wales organisation which represents the four Welsh regions - Dragons, Scarlets, Ospreys and Cardiff Blues - and sits on the Celtic Rugby board that runs the Pro14 tournament.
The new 14-team league which starts in September is split into two conferences of seven and there have been reports linking teams from USA, Spain and Germany joining the tournament.
"One of the benefits of going to a conference structure is we can continue to grow the competition," said Davies.
"It's not a domestic league. We've always had four nations every weekend with different styles of rugby, different philosophies.
"So if we've got five nations every weekend, why can't we have six?"
Media playback is not supported on this device
There are still four South African sides playing in Super Rugby with Davies not ruling out more sides from the country joining the Kings and Cheetahs.
"From a South African point of view, it would be sensible if they can continue to play New Zealand and Australia," said Davies.
"They'll want to retain both. They're now in a position where they have a choice.
"Would they seek to have more teams playing in the northern hemisphere? I believe so.
"It doesn't necessarily mean they'll have less playing in the southern hemisphere."
Davies believes the new competition, which will include 21 regular matches and play-offs, will be exciting.
"We've now got five of the top ten tier nations playing in one competition," said Davies
"It's pretty profound, the first time there's been any club competition that's transcended hemispheres."
Davies has been at the heart of delivering the radical expansion in the last few months but admits there will be doubters.
"It arrived late, it's been delivered in about a 12-week period," said Davies.
"It's been hard work from a very small group of people but absolutely worthwhile because of the scale of the change. It's not the end game, it's the end of the beginning.
"South African supporters can now watch rugby in their summer which they're excited about. Perhaps there's a lesson there for us.
"In any change there will be dissenting voices. The alternative is we stay the same and that isn't an option because if you stay the same in any form of life, you go backwards. We are not going backwards.
"I've met with various supporters and the overriding impression is excitement, a belief this is something new. Our aim was to have more big games and that's what we've got."
Davies believes the expanded Pro14 competition has ensured the tournament will be noticed by France's Top 14 and English Aviva Premiership bosses.
"I would like to think they're recognising the fact we woke up and something's happening," said Davies.
"The Aviva and Top 14 are strong, well-run, domestic competitions in big markets and we have to compete on different terms.
"I'd like to think the English and French clubs are looking at us and feeling it is worthwhile watching what we're doing.
"Instead of then looking at each other now, perhaps they have someone else in the room. If there's three in the race, we all go forward."
The Welsh regions will benefit from an additional £500,000 per region, although Davies would not be drawn on exact figures.
Davies stated that extra money would not be spent on travel costs to South Africa with additional revenue provided for the trips.
"We've got broadcast agreements in place in South Africa which are significant," said Davies.
"That's the first stage of the contribution to our clubs.
"It wouldn't be sensible to then dilute that with additional travel costs."


A Blackpool football fan who is accused of libelling the club's owners on the internet has told a court he has "never written anything defamatory".

Owen and Karl Oyston sued fan David Ragozzino for Â£150,000 over a post on website Another View From the Tower.
The 32-year-old said he had "limited financial means" and feared what would happen should the Oystons win the case.
The judge at Manchester Civil Justice Centre gave him 21 days to respond to the claim.
The application to default hearing was brought by the Oystons on the grounds Mr Ragozzino had failed to file a defence in time to their action.
He was supported at the court by dozens of Blackpool fans, who carried banners that criticised the Oystons' running of the club.
On Friday, fellow fan Stephen Sharpe apologised to the Oystons over his online comments, withdrawing his posts after accepting they were "false, defamatory and, in some cases, threatening".
On Saturday, about 1,000 fans staged a demonstration before the club's home game with Brighton, calling for the Oystons to relinquish control of the club.


Andy Murray faces Croat Ivo Karlovic in the French Open third round on Friday after surviving five-set scares in his first two matches in Paris.

Second seed Murray has spent seven hours and 14 minutes on court against Radek Stepanek and Mathias Bourgue.
Davis Cup captain Leon Smith says Murray's good form before Roland Garros may be behind his initial struggles.
"If it doesn't quite go that way in the early rounds here, there's a bit of frustration," Smith said.
Murray's meeting with big-serving veteran Karlovic is the second match on Court Suzanne Lenglen on Friday at approximately 11:00 BST.
The British number one warmed up for the French Open by beating Novak Djokovic in straight sets in the final of the Italian Open.
But, by his own admission, Murray has been well short of that level in Paris.
He posted an image of a Get Out of Jail Free card from the board game Monopoly on social media after fighting back to beat against world number 164 Bourgue.
Smith, who was also a childhood coach of Murray's, says the 29-year-old could rediscover his form as suddenly as it left him.
"He had an unbelievable last match against Novak Djokovic and then suddenly the timing's not quite there," he added.
"That's what happens in this crazy sport. It literally changes every single day - yourself, the opponent, the conditions."
Karlovic, 37, became the oldest man to reach the third round of a Grand Slam event since Jimmy Connors at the 1991 US Open by beating Australian wildcard Jordan Thompson 12-10 in the decider of his own five-set epic.
The world number 28 is the top server on the men's tour, averaging 23 aces a match and winning almost 95% of his service games over the past year.
He has lost all six of the matches that he has played against Murray, most recently being beaten in four sets in the last 16 at Wimbledon 2015.
Another big server could await Murray if he extends that winning run over Karlovic. American John Isner is seeded to be his last-16 opponent.


Alastair Cook has said he is "gutted" to be left out of England's World Cup squad after Eoin Morgan was confirmed as the new one-day captain.

Cook, 29, has been dropped from the 15-man squad to play matches in Australia next month and the World Cup.
"I'm gutted to be left out of the World Cup squad and it is likely to take me a while to get over the disappointment," he said.
England announced their World Cup squad on Saturday morning.
The decision to drop Cook was made following a selectors' meeting on Friday and follows a miserable year for the batsman in one-day cricket.
He failed to score a century in 45 one-day internationals and recently led England to a 5-2 series defeat in Sri Lanka, scoring only 119 runs in six matches.
England selector James Whitaker confirmed that Cook's lack of runs had prompted the decision to remove him as captain.
"Having reviewed the recent series against Sri Lanka, we came to the conclusion that there was no place for Alastair Cook amongst our strongest 15 one-day players," said Whitaker.
Morgan's first challenge as captain is to lead the side in a tri-series against Australia and India as warm-up for the World Cup in February.
He said: "It's a huge honour to captain England and I am delighted to be leading the one-day side.
"I firmly believe that with the players currently involved in the one-day set-up we have the makings of a very good one-day side, a young side that can surprise people at the World Cup.
"We all recognise we still have a lot of work to do on our one-day game but the potential of this group of players is huge and it is now up to us as players to turn that potential into consistent performances."
Like Cook, Morgan has also struggled for runs in recent times and scored only one half century in seven matches in Sri Lanka, but averages 71.16 in his eight previous matches as England one-day captain.
Paul Downton, managing director of the England and Wales Cricket Board, added: "I have complete confidence in the decision made by the selectors and having spent time with Alastair yesterday he accepts that it has been made in the best interests of the one-day side. "


A man in his 60s has been shot a number of times through the window of a house near Poyntzpass, County Armagh.

The shooting happened at about 22:00 GMT on the Tullymore Road.
The victim was taken to hospital for treatment.
His injuries are not believed to be life-threatening.


Two Scouts from the Highlands who contracted meningitis on a trip to Japan are said to be recovering.

The teenagers returned from the 2015 World Scout Jamboree at the weekend.
One of them - Brodie McMaster - was treated at Raigmore Hospital in Inverness, and has returned home. Health Protection Scotland said all close contacts had been identified and were being prescribed antibiotics.
Scouts Scotland said it was keeping everyone fully informed and supported.


An operation is under way to raise the Sewol ferry which capsized more than two years ago killing 304 people, mostly teenagers, in South Korea.

The raising of the Sewol, which sank on 16 April 2014, has been a central demand of the victims' families.
Many hope the bodies of the nine missing people will be recovered.
The disaster was one of the worst maritime disasters in South Korea in decades, and triggered widespread mourning.
The project, which will cost $73m (Â£47m), was announced last year by Seoul and is led by a Chinese consortium.
Preparatory work was completed early on Sunday morning, with the lifting of the bow section- seen as the most challenging part of the operation- to be conducted over two days.
The 6,825-ton ferry lies more than 40 metres (130 feet) beneath the surface of the water, off the south-western island of Jindo.
Officials have said  that the main hurdle will be lifting it from the seabed without it breaking up.
"The [lifting of the bow] operation takes up about 70% of the overall salvage project," Jung Seong-Wook, who is acting as a representative for the families of the victims, told AFP.
Once the bow is lifted 18 lifting beams will be placed underneath the ferry.
The Sewol may be raised by late July if the lifting operation goes smoothly, authorities have said.
In April last year, South Korean President Park Geun-hye promised that the vessel would be raised at the earliest opportunity.
The disaster was blamed on a combination of illegal redesigns, the overloading of cargo, the inexperience of the crew member steering the vessel, and lax government regulations.
The Sewol was carrying 476 people when it sank. The passengers included 325 students aged between 16 and 17 who were on a school trip to the holiday island of Jeju.


The UK government has said that comments made by Gerry Adams that Brexit will "destroy the Good Friday Agreement" are "totally without any basis in fact."

A spokesperson said the provisions set out in the Belfast Agreement are not undermined by the decision to leave the EU.
The statement added that there would be "no return to the borders of the past".
The Sinn FÃ©in President made the remarks at a conference on Saturday.
His comments were criticised by Ulster Unionist Party MLA Doug Beattie who called on Mr Adams to "explain exactly what he means".
Outlining plans for the UK leaving the EU on Tuesday, Prime Minister Theresa May said Brexit means leaving the European Customs Union.
Mr Adams said Northern Ireland should enjoy special status after Brexit, claiming it would not affect the constitutional settlement which secures its status as part of the UK.
"Taking the North out of the EU will destroy the Good Friday Agreement," he said.
"The British government's intention to take the North out of the EU, despite the wish of the people there to remain, is a hostile action.
"Not just because of the implications of a hard border on this island, but also because of its negative impact on the Good Friday Agreement.
"The British prime minister repeated her intention to bring an end to the jurisdiction of the European Court.
"Along with her commitment to remove Britain from the European Convention on Human Rights, this stand threatens to undermine the fundamental human rights elements of the Good Friday Agreement."
Following the comments a UK Government spokesperson said "none of the institutions and provisions set out in the Belfast Agreement, including those relating to human rights, are in any way undermined by the decision of the UK to leave the EU".
"The UK Government is fully behind the implementation of the Belfast Agreement and its successors, including Stormont House and Fresh Start," it said.
"There will be no return to the borders of the past.
"We are also working intensively to ensure that following the forthcoming election strong and stable devolved government that works for everyone is re-established in Northern Ireland."
On Tuesday, the Taoiseach (Irish Prime Minister) Enda Kenny re-iterated his wish for "a preservation of the seamless border that is there now" and welcomed the "greater clarity" provided by Mrs May in her address on Britain's planned approach to the Brexit negotiation process.


A former Norwich City footballer who battled with depression wants to set up a clinic in Norfolk to help players deal with mental health issues.

Darren Eadie said he wanted to create a centre on the coast where players can speak with "like-minded people who have been through it themselves".
"I know there are a lot of people who have suffered in the past and suffering right at the minute," he said.
He is hoping to get support from the Professional Footballers' Association.
"[Football] is a highly pressured environment, not just for the 90 minutes on a Saturday but throughout the week - you're constantly scrutinised by the press and fans," Eadie said.
"There's not many environments you can be in where you get that much stick week in, week out.
"You're under constant pressure to be role models for people."
Eadie said the "macho environment" of football changing rooms makes it difficult for players.
"It's not one of the places you would often get players admitting to those kind of situations," he said.
But he hopes providing a specialised clinic in a serene Norfolk setting will give players and their families vital support.
"You'd rather speak to someone who is in our kind of environment who has played the game rather than ringing up someone from a national charity and speaking to them," he said.
"It's about making it comfortable for them."


Britain's Shauna Coxsey won a second successive Bouldering World Cup overall title after victory at the Navi Mumbai event in India on Sunday.

The 24-year-old from Runcorn became Britain's first champion in the event's 17-year history when she won in 2016.
Coxsey needed to finish ninth or higher to guarantee back-to-back titles, but took gold in the penultimate event of the season in Mumbai.
Japan's Miho Nonaka finished second, with compatriot Akiyo Noguchi third.
Sport climbing - which includes bouldering - is one of five new sports confirmed for the 2020 Tokyo Olympics.