Ambulances were called to trampoline parks in the UK more than 300 times in a year, figures obtained by BBC 5 live's Daily programme show.

One park, Flip Out Stoke, called out an ambulance more than once a week on average. But Jump Lanes, Londonderry, had no callouts across the 12 months.
Statistics from a Freedom of Information request show callouts made by 30 parks in 12 months to April 2016.
More than 140 UK trampoline parks have opened since the first in 2014.
One park in Chester is investigating after three people broke vertebrae in their backs on the same day.
Operators insist the number of injuries is very small compared to the total number of users.
Thirteen ambulance trusts across the UK confirmed that, between April 2015 and April 2016, 30 parks required 315 ambulance call outs.
The figures showed:
Flip Out Stoke is a franchise of the same company behind Flip Out Chester, where an investigation into the injuries is under way.
Flip Out has closed the Jump Tower section of the Chester park.
It said the call out rates should be taken in the context of the number of users - 200,000 visitors have been to the Chester site since it opened in December 2016.
Another of the company's franchises, Flip Out Portsmouth, had a lower call out rate, with paramedics attending eight times in its first 106 days - an average of once every 13 days.
A broken limb was the top injury suspected [14 of the 65 call outs] with broken legs the most common.
The other most common suspected injuries were spinal, head, back and foot.
Student George Magraw, 21, was one of the three people who broke their back on the same day jumping from Flip Out Chester's 4m high 'Tower Jump'.
He told BBC Radio 5 Live: "I'd been jumping on the trampolines for ten minutes when I moved on to the Tower Jump.
"I jumped off the ledge just how I'd been told in the safety video but as soon as I landed I was in pain.
"I crawled out of the foam pit and stood up. I could definitely feel that the bone wasn't right.
"The staff gave me first aid and offered to ring an ambulance but my dad was only minutes away so he took me instead.
"When I arrived at A&E I was quickly put on a bed and taken for an X-Ray. It was then they told me I'd broken my back."
George's transfer to a specialist unit in Walton was delayed because the centre was already dealing with another customer injured on the jump.
His mother, Janet Magraw, is now warning parents to understand the risks: "I always thought that going to a trampoline park, it's a soft landing and everything's okay.
"I've since heard from lots of medical staff that that's not the case - it's quite a dangerous place to be.
"I personally wouldn't recommend anybody going to them. At half term it was sickening me that there was a big queue of little kids going into that place.
"As a mum, you just really feel it could be life-changing."
A spokesman for Flip Out Chester said since its December 2016 opening, around 200,000 people had visited and it had "an excellent safety record".
"We welcome feedback from our customers and we are investigating these claims to establish exactly what happened," he said.
CEO at Oxygen, David Stalker said it got the design of their park wrong when it first opened.
He said: "The trend was towards opening up spaces, rather than zoning the trampolines into smaller areas as we do now.
"The more open space you have, the more speed you can gain. The result was more injuries."
He added: "We've now altered the designs for future parks and changed the layout at Southampton."
One of the smallest parks, Jump Lanes in Londonderry, which has around 25,000 visitors a year, had the fewest call outs - none in 12 months.
Air Hop in Guildford is one of the largest parks. Its smaller site in Bristol saw fewer callouts with eight in 193 days - one every 24 days.
Spokesman Chris Gilmour said trampoline parks should be viewed in context of other activities that carry risk.
He said: "Hospitals will tell you that, yes, they get injuries from trampoline parks but they see worse from people playing football or rugby.
"When you look at the percentage of customers who are injured it's in the hundredths of a percent."
The BSI [British Standards Institution] published standards for trampoline parks, at the request of the industry, earlier this month.
They include minimum specifications for the number of stewards and rules on specific safety features.
Peter Brown, chair of the UK's largest industry body the International Association of Trampoline Parks UK [IATP] said many parks were already up to standard.
New parks would have to comply and inspections would begin in August.
"Any issues we find will have to be put right within a reasonable timeframe, depending on how significant it is. In the most severe cases we will insist attractions are closed until fixed."
The number of parks in the UK has increased sharply since the first one opened in May 2014 - inspired by a craze that started in 2004 in the United States.
Thirty-seven had opened by November 2015, rising to 110 by November 2016, and 144 in early March 2017.
By Easter 2017, the IATP estimates there will be 150 parks in operation across the UK, with at least 15m visitors per year.


Solar Impulse, the zero-fuel aeroplane, has flown the first leg across the continental United States in its attempt to fly around the world.

It left Mountain View, California, at dawn on Monday and landed 16 hours later in Goodyear, a suburb of Phoenix, Arizona.
It was the 10th leg of its round the world quest.
Swiss adventurer Andre Borschberg was at the controls, having taken over from Bertrand Piccard.
Piccard flew Solar Impulse to the West Coast of the US from Hawaii just over a week ago.
The latest stint was relatively short - 1,113 km.
Take-off from the famous Moffett Airfield occurred at 05:03 PDT (12:03 GMT) and the plane landed in Phoenix at 20:55 PDT.
The team has traversed America before, in 2013. That crossing was undertaken in the prototype predecessor to the current aircraft. But it does mean the weather conditions the Solar Impulse is likely to encounter will be well understood.
Piccard and Borschberg are aiming to get to New York by the start of June, to begin preparations for the big Atlantic crossing.
Solar Impulse started its circumnavigation of the globe in March of last year in Abu Dhabi.
It flew over Oman, India, Myanmar and China before flying to Japan, from where it made a 8,924km (5,545-mile) passage to Hawaii.
That five-day, five-night journey set a record for the longest duration, non-stop, solo aeroplane flight.
But it also resulted in damage to the plane's batteries, forcing the team into some lengthy repairs.
And only when the days started stretching out again in the Northern Hemisphere could the team think about getting back in the air.
With 17,000 photovoltaic cells on its top surfaces, the plane gets all its energy from the sun.
These power the craft's propellers during the day but also charge batteries that the vehicle's motors can then call on during the night.
Solar Impulse is not intended to be a vision of the future of aviation. Rather, it is supposed to be a demonstration of the current capabilities of solar power in general.
The team's campaign is called "the future is clean".
Mr Piccard and Mr Borschberg have been working on the Solar Impulse project for more than a decade.
A plane that is wider than a 747 jumbo jet but weighs just 2.3 tonnes poses some unique challenges:
LEG 1: 9 March. Abu Dhabi (UAE) to Muscat (Oman) - 772km; 13 Hours 1 Minute
LEG 2: 10 March. Muscat (Oman) to Ahmedabad (India) - 1,593km; 15 Hours 20 Minutes
LEG 3: 18 March. Ahmedabad (India) to Varanasi (India) - 1,170km; 13 Hours 15 Minutes
LEG 4: 18 March. Varanasi (India) to Mandalay (Myanmar) - 1,536km; 13 Hours 29 Minutes
LEG 5: 29 March. Mandalay (Myanmar) to Chongqing (China) - 1,636km; 20 Hours 29 Minutes
LEG 6: 21 April. Chongqing (China) to Nanjing (China) - 1,384km; 17 Hours 22 Minutes
LEG 7: 30 May. Nanjing (China) to Nagoya (Japan) - 2,942km; 1 Day 20 Hours 9 Minutes
LEG 8: 28 June. Nagoya (Japan) to Kalaeloa, Hawaii (US) - 8,924km; 4 Days 21 Hours 52 Minutes
LEG 9: 21 April. Kalaeloa, Hawaii (US) to Mountain View, California (US) - 4,523km;  2 Days 17 Hours 29 Minutes
LEG 10: 2 May. Mountain View, California (US) to Phoenix, Arizona (US) - 1,199km; 15 Hours 52 Minutes
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos


Britain's Chris Froome extended his Vuelta a Espana lead by one second as Tomasz Marczynski claimed victory on stage six.

BMC's Tejay van Garderen, who began the day second overall, 10 seconds behind Froome, was involved in a crash and lost time on the Team Sky rider.
Orica-Scott's Esteban Chaves moves up to second, 11 seconds behind Froome.
Froome, 32, is aiming to become the third man to win the Vuelta and the Tour de France in the same year.
Van Garderen crashed when descending the day's final climb, on which Froome had defended himself from several Alberto Contador attacks.
At one point Van Garderen was almost two minutes behind Froome's group, but the American managed to reduce that gap, finishing only 17 seconds slower, despite suffering a second crash in the closing kilometres.
He is now in fourth place overall, 27 seconds behind Froome.
Spaniard David de la Cruz, who started the day in fifth, also lost 17 seconds on Froome, and he fell to sixth, with Italy's Vincenzo Nibali moving above him.
Poland's Marczynski was one of three breakaway riders contesting a sprint finish at the end of Thursday's 204.4km ride from Vila-real to Sagunt, in Valencia province.
Find out how to get into cycling with our special guide.
The Lotto-Soudal rider's countryman Pawel Poljanski of Bora-Hansgrohe was second, with Spain's Enric Mas of Quick-Step Floors in third.
With just under 14km to go it appeared the breakaway was about to be reeled in and the lead group's fourth rider, Luis Leon Sanchez, rejoined the peloton with the split down to six seconds.
However, the three remaining riders managed to break clear once again, and Spaniard Sanchez eventually finished fourth, eight seconds off the pace.
Froome's group finished 26 seconds further back.
"The guys did another amazing job today from start to finish. They were all over that race and I've got them to thank for still being in this jersey," he said.
"Alberto [Contador] may have already lost time in the overall standings but I have to follow when he goes. He's still a danger and has shown just how strong and tenacious he is. He will fight all the way for the rest of this race I'm sure."
Friday's stage is a 207km ride from Lliria to Cuenca that takes in three category-three climbs.
1. Tomasz Marczynski (Pol/Lotto-Soudal) 4hrs 47mins 02 secs
2. Pawel Poljanski (Pol/Bora-Hansgrohe) Same time
3. Enric Mas (Spa/Quick-Step Floors)
4.  Luis Leon Sanchez (Spa/Astana) +8secs
5. Jan Polanc (Slo/UAE Team Emirates)
6. Warren Barguil (Fra/Sunweb) +26secs
7.  Giovanni Visconti (Ita/Bahrain-Merida)
8. Chris Froome (GB/Team Sky)
9.  Fabio Aru (Ita/Astana)
10. Jack Haig (Aus/ Orica-Scott)
1. Chris Froome (GB/Team Sky)
2. Esteban Chaves (Col/Orica-Scott) +11secs
3. Nicolas Roche (Ire/BMC) +13secs
4. Tejay Van Garderen (US/BMC)+27secs
5. Vicenzo Nibali (Ita/Bahrain-Merida) +36secs
6. David De La Cruz (Spa/Quick-Step Floors) +40secs
7. Fabio Aru (Ita/Astana) +49secs
8. Adam Yates (GB/Orica-Scott) +50secs
9. Michael Woods (Can/Cannondale) +1mins 13secs
10. Simon Yates (GB/Orica-Scott) +1mins 026secs


Depression can make us physically older by speeding up the ageing process in our cells, according to a study.

Lab tests showed cells looked biologically older in people who were severely depressed or who had been in the past.
These visible differences in a measure of cell ageing called telomere length couldn't be explained by other factors, such as whether a person smoked.
The findings, in more than 2,000 people, appear in Molecular Psychiatry.
Experts already know that people with major depression are at increased risk of age-related diseases such as cancer, diabetes, obesity and heart disease.
This might be partly down to unhealthy lifestyle behaviours such as alcohol use and physical inactivity.
But scientists suspect depression takes its own toll on our cells.
To investigate, Josine Verhoeven from the VU University Medical Centre in the Netherlands, along with colleagues from the US, recruited 2,407 people to take part in the study.
More than one third of the volunteers were currently depressed, a third had experienced major depression in the past and the rest had never been depressed.
The volunteers were asked to give a blood sample for the researchers to analyse in the lab for signs of cellular ageing.
The researchers were looking for changes in structures deep inside cells called telomeres.
Telomeres cap the end of our chromosomes which house our DNA. Their job is to stop any unwanted loss of this vital genetic code. As cells divide, the telomeres get shorter and shorter. Measuring their length is a way of assessing cellular ageing.
People who were or had been depressed had much shorter telomeres than those who had never experienced depression. This difference was apparent even after lifestyle differences, such as heavy drinking and smoking, were taken into account.
Furthermore, the most severely and chronically depressed patients had the shortest telomeres.
Dr Verhoeven and colleagues speculate that shortened telomeres are a consequence of the body's reaction to the distress depression causes.
"This large-scale study provides convincing evidence that depression is associated with several years of biological ageing, especially among those with the most severe and chronic symptoms," they say.
But it is unclear whether this ageing process is harmful and if it can be reversed.
UK expert Dr Anna Phillips, of the University of Birmingham, has researched the effects of stress on telomere length.
She says telomere length does not consistently predict other key outcomes such as death risk.
Further, it is likely that only a major depressive disorder, not experience of or even a lifetime of mild-to-moderate depressive symptoms, relates to telomere length, she said.


Ryan Edwards has signed a two-year contract extension with Partick Thistle, keeping the midfielder at Firhill until at least 2020.

The Australian, 23, featured in all of the club's Scottish Premiership fixtures as Thistle secured a highest top-flight finish (sixth) since 1981.
Edwards has made 55 appearances for Thistle since joining Alan Archibald's side from Reading in September 2015.
"I'm delighted to sign, it was a really easy decision," he told Jagzone TV.
"The club have been great with me since day one, and made my time on and off the pitch really easy-going and enjoyable."


The pound has reached a more-than seven year high against the euro, a day after the European Central Bank (ECB) began its government bond buying programme.

Sterling rose 1% to hit €1.40 for the first time since December 2007.
It means UK holidaymakers to the eurozone will have just over 15% more spending power than a year ago.
City analysts said continued fears over a Greek exit from the eurozone had also helped push the pound higher against the single currency.
Last year, the pound was trading at €1.205, meaning holidaymakers could expect €1.18 for every pound they exchanged.
UK holidaymakers to Europe would have received €707 for every £600 they exchanged a year ago, but they would get €822 today.
The rise in sterling came after the head of the eurozone finance ministers' group called on Greece to "stop wasting time" and engage in serious talks on reform.
At a meeting in Brussels on Monday, Dutch finance minister Jeroen Dijsselbloem said there had been little progress made since discussions two weeks ago.
European creditors want to approve a detailed list of reforms before they release any loans to Greece.
Jeremy Cook, chief economist and head of currency strategy at foreign exchange traders World First, said alongside concerns over Greece, the ECB's bond buying programme and negative bank deposit interest rates were "hammering" the single currency.
The ECB began its €60bn (£42.8bn) monthly bond buying programme on Monday.
On Tuesday, sterling rose as high as €1.4091, up more than 1%.
Announcing the start of the programme last week ECB president Mario Draghi said the bank would continue to buy bonds into the second half of 2016.
However, Mr Draghi kept the door open to continuing the programme past this deadline, should inflation in the eurozone have failed to return to near normal levels.
The ECB has a remit to keep inflation at or slightly below 2%. But persistent low inflation throughout 2014 stoked fears that the currency bloc could fall into deflation as consumers held off spending and businesses postponed investment as price fell.
Mr Draghi said he expected domestic demand to improve over the course of the year, as the effects of the bond-buying programme began to be felt, and that demand for European exports, would increase "as prices become more competitive," thanks to a weaker euro.
He added he expected the lower oil price to be helpful over the next few months.
Last week the ECB raised its forecast for eurozone economic growth to 1.5% in 2015 from its previous December forecast of 1%.
It also upped its forecast for economic growth to 1.9% in 2016, and to 2.1% for 2017.
Also last week, official figures confirmed that the eurozone economy grew by 0.9% in 2014.
Elsewhere, Germany's BGA trade association raised its forecast for exports, expecting the weaker euro to offset uncertainty surrounding crises in Greece and Ukraine.
It said it expected exports to grow 4.5% this year, up from a previous forecast of 4%. Imports are forecast to rise 4% which would increase Germany's trade surplus to a record €231bn, BGA said.


Former footballer Paul Gascoigne has told the High Court he was "scared to speak to anybody" by phone during the 10 years his voicemail was hacked by Mirror Group journalists.

The former England international, 47, said the journalists had "ruined his life".
He said he had known his phone had been hacked but no-one had believed him.
Describing the experience as "horrendous", Mr Gascoigne linked the phone hacking with his alcoholism.
The former Tottenham Hotspur, Newcastle United and Everton footballer is complaining about 18 articles, all accepted to have been the product of illegal activity.
Mr Gascoigne told the court he would often change his phone number "several times a month" because he knew his phone was being hacked.
But his family had not believed his phone was being hacked, he said, while his therapist had told him he was "paranoid" and "going through a mental disorder".
His voice hoarse and shaking with emotion, he said: "I knew I was getting hacked by the Mirror.
"This continued for ages. Phone calls to my father and family were getting blocked so I changed my mobile.
"It happened again so I kept on changing mobiles, five or six times a month."
Mr Gascoigne said the experience of being the victim of phone hacking had been "so scary".
He said: "I was scared to speak to anybody... my parents, my family and kids, it was just horrendous.
"And people can't understand why I became an alcoholic."
After speaking briefly, Mr Gascoigne was told he would not face cross-examination by Matthew Nicklin QC, for Mirror Group Newspapers (MGN), and his evidence was going unchallenged.
He replied: "I have waited 15 years to be sat here so I am disgusted, really.
"I would like to trade my mobile phone in for a coffin because these guys have ruined my life. I have no life."
In a written statement supplied to the court, Mr Gascoigne said constant media pressure had made it very difficult for him to lead a normal and private life and had led to his family not being as close as they once were.
He said he had suffered from alcohol dependency over a number of years and had also had treatment for drug use and addiction to the drink Red Bull.
Between 2000 and 2006 he had wrongly accused people close to him, such as his stepdaughter Bianca, of going to the newspapers with stories about him, he said.
"I became obsessed about being monitored. I felt that I was being watched or listened into all the time for years and the pressure on me because of that was more than I think any sane person could bear," he said.
Former EastEnders actress Lucy Taggart, previously known as Lucy Benjamin, followed Mr Gascoigne into the witness box and described the effect the publication of a string of articles had had on her.
Her voice breaking, she said: "With each one I always felt like I had to pick myself up and dust myself off and carry on.
"But on the following day or following week there would be another article about something else and it felt like I was being punched and battered and bruised.
"It felt I was in a boxing ring without any gloves."
When phone hacking appeared in the news, Ms Taggart said she "knew it was the Mirror that had done it".
She said: "The Mirror were the worst culprit as far as I was concerned.
"The Mirror wrote the dirtiest stories and I always felt like the articles were a personal attack."
She added: "I feel like the people who worked at the paper were sadistic and their mission was to destroy people's lives."
MGN has admitted publishing 17 articles about Ms Taggart between 2000 and 2006 as a result of phone hacking.
Ms Taggart said she believed MGN had "slaughtered" her over the seven years she was targeted, describing the extent of the intrusion as "nothing short of psychological abuse".
The hearing at the High Court in London is considering what compensation should be paid by MGN to BBC creative director Alan Yentob, soap stars Shane Richie, Shobna Gulati and Lucy Taggart, former footballer Paul Gascoigne, actress Sadie Frost, TV producer Robert Ashworth and flight attendant Lauren Alcorn.
Seven of the claimants have referred to at least 109 published stories.
The court has previously heard phone hacking at the newspaper group was on an "industrial scale".
MGN said the hacking was carried out by a "trusted inner circle".


The government and military in Myanmar are holding landmark peace talks with armed ethnic groups as part of efforts to bring an end to decades of conflict.

The meeting in the capital Nay Pyi Taw, involving 17 groups, is being opened by Aung San Suu Kyi and attended by UN Secretary General Ban Ki-moon.
Negotiations on a permanent peace are expected to last months if not years.
But opening the five-day talks, Aung San Suu Kyi said unity was essential for Myanmar's future.
"So long as we are unable to achieve national reconciliation and national unity, we will never be able to establish a sustainable and durable peaceful union," she told attendees.
"Only if our country is at peace will we be able to stand on an equal footing with the other countries in our region and across the world."
Mr Ban has said the talks are "an important first step".
Myanmar, also known as Burma, has been plagued by violence since gaining independence in 1948, involving ethnic minority groups seeking independence or greater autonomy and angry at the dominance of the Burman ethnic majority.
The former military-backed government had reached truces with some groups, but has never managed to secure a nationwide deal. Sporadic violence has killed or displaced tens of thousands of people over the years.
Myanmar's de factor leader Aung San Suu Kyi has said securing peace is a priority for her National League for Democracy, which won elections last year.
All armed ethnic groups, which have tens of thousands of fighters between them, were invited and most are attending, along with representatives from the government, army, political parties and civil society.
They include the Karen, Kachin, Shan and Wa, all of which agreed to put down their weapons to attend.
But three smaller armed groups have not been invited, because they would not agree to the terms and are still fighting government forces.
The BBC's Jonah Fisher in Nay Pyi Taw says the armed groups have been brought to the table by vague promises of a more federal Myanmar with power and resource sharing.
But the military, which still holds 25% of seats in parliament, sees its role as resisting the break-up of Myanmar, so are likely to oppose any such move. It also remains unclear, he adds, how much devolution of power Suu Kyi actually wants.
For it's part the army would like the armed groups to begin disarming as soon as possible, and wants the 2008 constitution which it effectively drafted at the heart of any peace deal. The group would like to hold onto their arms until a deal is reached.
Our correspondent says the complexity and scale of the talks are daunting, but they are almost certainly Myanmar's best chance for nationwide peace in nearly 70 years.
Mr Ban has also used his visit to Myanmar to raise concern on the separate issue of the plight of the Rohingya minority.
He said the marginalised Muslim ethnic group, who are not officially recognised by Myanmar, "deserve hope".
Tens of thousands of Rohingya are living in temporary camps in northern Rakhine state after being displaced by deadly communal violence in majority Buddhist Myanmar in 2012.
The government, along with many Burmese, consider the Rohingya to be illegal Bangladeshi migrants. They are not formally recognised by law and have no voting rights.
Mr Ban told reporters on Tuesday the Myanmar government "has assured me about its commitment to address the roots of the problem".
He said the Rohingya "need and deserve a future, hope and dignity. This is not just a question of the Rohingya community's right to self-identity".
Last week, Ms Suu Kyi, who has been accused of ignoring the Rohingya, set up a commission to investigate the issue, led by former UN Secretary General Kofi Annan.


Manchester United midfielder Juan Mata says Leicester's unlikely march to the title is a "little bit of fresh air" blowing through the Premier League.

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If Leicester defeat United at Old Trafford on Sunday they will secure a first top-flight championship in their 132-year history.
"They showed great character, commitment and passion," said Mata.
"They are really close to doing it. But hopefully it doesn't happen at Old Trafford. They can wait another week."
The Spain international added: "It is good for football in a way because it is a little bit of fresh air. But my wish is that we were winning the league."
Speaking to BBC Sport, Mata also discussed how United must win all four of their remaining league games to stand a chance of qualifying for the Champions League and revealed his disappointment at not competing for the title.
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Even if Leicester lose on Sunday, a seven-point advantage over nearest rivals Tottenham means they could still wrap up the title if Spurs lose to Chelsea on Monday night.
It is the kind of scenario Mata hoped he would be involved in when he joined the then-reigning champions in a £39.1m deal from Chelsea in January 2014.
United have not won a trophy since, finishing seventh and fourth in Mata's first two seasons. They sit fifth at present, five points off the top four and 17 behind Leicester.
"We did not do well enough to win the title," Mata said, who was speaking at the launch of a two-year spell as ambassador at global children's charity streetfootballworld.
"Leicester can make their dreams come true. In the beginning of the season you could be surprised but after that, when you see the way they play and the way they defend. They play like a team and get results.
"I really like Riyad Mahrez. He is playing the best football of his life. But it is not just about one player."
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In their second season under manager Louis van Gaal, United were expected to use their return to the Champions League as a launch pad towards competing for major honours again.
They briefly led the Premier League in November but a run of six games without a win ended their challenge, with Van Gaal pointing to a huge injury list.
Manchester City and Arsenal remain five points in front - having played a game more - even though United have won six of their last eight games.
"It has not been an easy season," said Mata. "Manchester United should not judge a season as successful solely because they have qualified for the Champions League.
"But you have to react to the reality."
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With Manchester City and Arsenal still to play each other, Mata says 12 points from United's final four games will be enough for the FA Cup finalists to claim a Champions League place.
And if they can beat Crystal Palace at Wembley on 21 May as well, he does not think the season would look so bad.
"If we don't win every game, we will be depending on the other teams too much," he said. "Also, the club hasn't won the FA Cup for a few years.
"If we won that very special trophy and finished third or fourth, maybe the season is not as bad as it looked before. Hopefully we could build from that."
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Have you added the new Top Story alerts in the BBC Sport app? Simply head to the menu in the app - and don't forget you can also add score alerts your football team and more.


Two senior council officers at Caerphilly council have been charged following a police investigation into pay rises given to senior staff.

The council's chief executive Anthony O'Sullivan, 54, and his deputy Nigel Barnett, 51, face charges of alleged misconduct in a public office.
The council's head of legal services, Daniel Perkins, 48, is due to be charged with the same alleged offences.
They will appear at Bristol Magistrates' Court on 22 April.
Avon and Somerset Police, which is the investigating force, said the misconduct was alleged to have taken place between June and October 2012.
Police were called in after a Wales Audit Office (WAO) report raised concerns about pay increases awarded to senior staff.
This included a salary increase of Â£26,000 given to Mr O'Sullivan, approved by councillors on the recommendation of a report he wrote.
The decision sparked protests by staff and trade unions because it came at a time when the bulk of the council's staff were on the third year of a pay freeze.
The council eventually reversed the decision and awarded lower pay rises instead.
A spokeswoman for Caerphilly council said: "We can confirm that two senior officers have been formally charged by Avon and Somerset Police and a third officer has been reported for summons in connection with the offence of misconduct in a public office.
"We are unable to offer any further comment other than to say we continue to fully co-operate with the police with their enquiries."


Ulster pair Louis Ludik and Darren Cave face spells on the sidelines after picking up injures in Friday's Pro12 defeat by Connacht in Galway.

Ludik is out for four-six weeks with a fractured cheekbone and Cave could miss four weeks because of a calf tear.
However, Charles Piutau is among six players set to return for the European Champions Cup opener against Bordeaux.
Stuart Olding, Luke Marshall, Andrew Trimble, Franco van der Merwe and Dan Tuohy are also expected back.
Having Piutau, Marshall (both concussion), Trimble (toe), van der Merwe, Tuohy (both ankle) and Olding (right adductor) available after injury would be a major boost for Kiss ahead of Sunday's trip to France.
Utility back Ludik and centre Cave were both forced off as Ulster suffered their first Pro12 loss of the campaign.
Ulster remain top of the Pro12 standings although just one point separates the top four.


A Vatican official has said the awarding of the Nobel Prize for Medicine to British IVF pioneer Robert Edwards is "completely out of order".

Ignacio Carrasco de Paula, head of the Pontifical Academy for Life, said the award ignored the ethical questions raised by the fertility treatment.
He said IVF had led to the destruction of large numbers of human embryos.
Nearly four million babies have been born using IVF fertility treatment since 1978.
Monsignor Carrasco, the Vatican's spokesman on bio-ethics, said in-vitro fertilisation (IVF) had been "a new and important chapter in the field of human reproduction".
But he said the Nobel prize committee's choice of Prof Edwards had been "completely out of order" as without his treatment, there would be no market for human eggs "and there would not be a large number of freezers filled with embryos in the world", he told Italy's Ansa news agency.
"In the best of cases they are transferred into a uterus but most probably they will end up abandoned or dead, which is a problem for which the new Nobel prize winner is responsible."
In his statement, Monsignor Carrasco stressed that he was speaking in a personal capacity.
The Nobel medicine prize committee in Sweden said Prof Edwards' work had brought "joy to infertile people all over the world".
"His achievements have made it possible to treat infertility, a medical condition afflicting a large proportion of humanity, including more than 10% of all couples worldwide," it said.
Prof Edwards efforts in the 1950s, 60s and 70s led to the birth of the world's first "test tube baby", Louise Brown, in July 1978.
Ms Brown said the award was "fantastic news".
"Me and mum are so glad that one of the pioneers of IVF has been given the recognition he deserves," she said.
"We hold Bob in great affection and are delighted to send our personal congratulations to him and his family at this time."


Donald Trump has detailed his foreign policy in a speech, a day after sweeping to a win in five US primaries.

Mr Trump, the frontrunner for the Republican candidacy in the 2016 presidential race, said he would pursue an "America First" policy.
He called the foreign policy of President Barack Obama's administration "a complete and total disaster".
On Tuesday, Mr Trump called himself the Republican "presumptive nominee" after his primary wins.
He claimed victories in Connecticut, Delaware, Rhode Island, Maryland and Pennsylvania.
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Before the speech, he promised it would not be a "Trump doctrine", and that he would retain some flexibility to make changes if elected.
Much of his speech focused on what he called the "weakness, confusion and disarray" of the Obama administration, and his hope of reversing it.
Before the audience in Washington, he vowed to "shake the rust off America's foreign policy".
On Islamic State
Mr Trump said that, under his administration "their days are numbered - I won't tell them when, and I won't tell them how".
He had previously said he would weaken so-called Islamic State (IS) by cutting off their access to oil, and supported waterboarding and other strong interrogation methods against them. He did not return to these proposals on Wednesday.
"Containing the spread of radical Islam must be a major foreign policy goal of the United States and indeed, the world," he said on Wednesday, adding that he would work closely with US allies in the Middle East to combat extremism.
On the Iran nuclear deal
Mr Trump reiterated his opposition to last year's nuclear agreement with Iran, in accordance with which six world powers led by the US agreed to lift sanctions on Iran in exchange for limits on Tehran's nuclear programme.
Mr Trump accused President Obama of snubbing what he called America's great friend Israel and treating Iran with "tender love and care".
"He [Obama] negotiated a disastrous deal with Iran, and then we watched them ignore its terms even before the ink was dry. Iran cannot be allowed to have a nuclear weapon," he said.
In a speech last month, Mr Trump said he wanted to "dismantle" the agreement if elected.
On Nato and other powers
New talks would be sought with the United States' allies in trans-Atlantic alliance Nato, Mr Trump said. He said he would try and reshape the organisation's structure and discuss a "rebalancing" of US financing towards it.
Mr Trump said he would also aim to hold talks with Russia to seek common ground, possibly over Islamist extremism.
"Some say the Russians can't be reasonable," he said. "I intend to find out."
China, he said, "respects strength, and by letting them take advantage of us economically like they are doing, we are losing all their respect". He said he would seek to "fix our relations with China" but did not suggest how.
On US allies
"The countries we defend must pay for the cost of this defence," he said. "If not, the US must be prepared to let these countries defend themselves. We have no choice."
Speaking to the New York Times last month about the US-Japan relationship, he said: "If we're attacked, they do not have to come to our defence, if they're attacked, we have to come totally to their defence. And that is a, that's a real problem."
Nearly 30 years ago, Donald Trump topped the best-seller list with his salesman's manifesto, The Art of the Deal. His vision presented on Wednesday was all about how he could get the best deal for the US.
Since the end of the Cold War, the US had been weak, he said. Now it would be strong. The US had been taken advantage of by its allies, he contended, but he would make them pay their fair share, while assuring them that they could trust the US.
How? Through his deal-making prowess and policy "coherence".
Although Mr Trump's much-heralded speech was scripted and delivered via teleprompter, content-wise it was essentially a calmly intoned reprise of the views he has expressed throughout the campaign.
While that may not fly with a foreign policy establishment that has teetered on the verge of panic over some of Mr Trump's more controversial proposals, this "America first" rhetoric has been at the heart of the message that has shot him to the top of the Republican heap.
Mr Trump once said he was his own best foreign policy adviser, but, in recent months, has expanded his backroom team. Some of his appointments have proved controversial.
The team is led by Republican Senator Republican Senator Jeff Sessions of Alabama, a former federal prosecutor.
Another member, retired Gen Joseph Schmitz, resigned from the military in 2005 amid accusations of misconduct. However, Mr Schmitz was never charged with wrongdoing.
Another adviser, Walid Phares, was criticised when he was named as part of Mitt Romney's foreign policy team in 2011.
Muslim advocacy groups took issue with Mr Phares's close ties to right-wing Christian militia groups during the Lebanese civil war.
"There was a lot in the talk that I would absolutely agree with," Jim Gilmore, a former 2016 Republican candidate, said. "On the other hand, there is a lot in this speech that contradicts that, that talks about pulling back, confronting if you will our allies much more."
White House spokesman Josh Earnest said: "I think when it comes to this president's foreign policy, there is no denying that the United States is safer and stronger than we were when President Obama took office back in January of 2009."
Mr Earnest also said other alliances had been strengthened, and that the new pivot to Asia had benefits the US economically and strategically.


A Libyan man has been arrested on suspicion of conspiracy to murder PC Yvonne Fletcher three decades ago.

PC Fletcher, 25, died after being shot while policing a demonstration outside the Libyan Embassy in London in 1984.
Scotland Yard described the arrest of the man, in his 50s, as a "significant development".
He was detained on Thursday morning in south-east England and is in custody. He was also held on suspicion of money laundering.
Two other Libyan nationals - a woman in her 40s and a man in his 30s - were also arrested on suspicion of money laundering at separate addresses in London and south-east England.
They were later released on bail pending further enquiries, Scotland Yard said.
PC Fletcher's family said in a statement that her father Tim had recently died, with his "one regret in life" being that he had "never witnessed any justice".
The Met is offering a reward of up to Â£50,000 for information.
PC Fletcher was one of 50 officers policing a protest against Col Muammar Gaddafi's regime outside the embassy when she was hit by a burst of gunfire from a first-floor window.
The death of Gaddafi in 2011 and the subsequent regime change provided new lines of enquiry, with police visits to Libya since then unearthing "new and fresh evidence".
The force has released images of 14 people they want to trace from a pro-Gaddafi group, which was holding a counter-demonstration nearby.
Video footage of the demonstration and shooting has also been released.
The 54-second clip shows the chaotic moments after shots were fired, with dozens of demonstrators falling to the ground after a loud bang is heard.
Commander Richard Walton, head of counter-terrorism at Scotland Yard, said: "The day Yvonne was shot remains one of the saddest and darkest days in the history of British policing.
"We have never lost our resolve to solve this case and to bring to justice those who conspired to commit this act of murder."
He said a number of shots were fired at 10:17 on the morning of 17 April, 1984, hitting PC Fletcher in the back. Ten anti-Gaddafi campaigners were also injured in the shooting.
Mr Walton said a pistol and an automatic weapon are thought to have been used. Police believe the shooting was part of the "stray dogs campaign" arranged from Libya to attack overseas dissidents.
PC Fletcher's family said: "Recently we have had to come to terms with another loss through the death of Yvonne's father, Tim.
"His one regret in life was that no one had been arrested... [he] never witnessed any justice.
"Resolving this crime is still important to all the family.
"Any information, however small, can help bring closure for the family and we therefore continue to support the Metropolitan Police in their ongoing investigation."
Mr Walton appealed for anyone in the area of the embassy, in St James's Square, on the day of the shooting to contact police - even if they had already done so in the past.
He said: "In particular, we want to speak to those who attended the Libyan People's Bureau on the day... to protest, either against or in favour of Gaddafi.
"There were a number of witnesses who were part of the pro-Gaddafi counter-demonstration, orchestrated from within the Libyan People's Bureau, whom we have never spoken to.
"We appeal particularly to these people to come forward and speak to us now, even after 31 years."
The shooting of PC Fletcher sparked an 11-day siege of the Libyan embassy.
Because of diplomatic immunity, the Met could not search the bags of the diplomats and staff who were subsequently deported.
Diplomatic ties between Libya and the UK were severed following the killing.


A man dubbed the "godfather" of football hooliganism in Wolverhampton has been banned from all professional grounds in the country.

Gilroy Shaw, 47, was given the Football Banning Order at Birmingham Magistrates' Court on Monday.
Shaw, of Selwyn Road, Bilston, has been a "prominent figure in hooligan circles for almost 30 years," West Midlands Police said.
The order bans Shaw from attending matches for five years.
Wolves supporter Shaw has been banned from its home ground Molineux since 2010 and must also stay outside a five-mile exclusion zone at stadiums involving the club for three hours before and after kick-off.
West Midlands Police said it applied for the civil injunction after amassing a "huge backlog of evidence" detailing his involvement in football violence and association with "risk" supporters.
Ch Insp Nick Rowe said: "Shaw is a familiar face at fixtures at home and abroad and tends to be at the centre of disorder, inciting rival fans, threatening violence, and getting involved in mass brawls.
"He has been the number one target for us for some time but in recent years has become almost a godfather figure, organising and instigating violence and then slipping away while his minions throw the punches, hurl the missiles or damage property."
A total of 166 people are currently the subject of Football banning Orders (FBOs) in the West Midlands but most orders are "tagged on to" criminal court convictions, the force said.


David Cameron has rejected claims that Liverpool is being treated unfairly in terms of government funding.

The prime minister said cuts to the city's Whitehall grants this year were no higher than the average in England.
He told BBC Radio Merseyside that the council had increased its overall budget this year and was also adding to its back-up financial reserves.
The city's mayor has invited ministers to take a look at its accounts, saying it is being "stabbed in the back".
Joe Anderson, former leader of the Labour-run council in Liverpool who was elected mayor last year, said the city had already had to make £176m in cuts and its budget was set to fall by a further £156m by 2018.
He claimed the city had been disproportionately affected by the budget squeeze across local government compared with councils in more prosperous areas, making it increasingly hard to fund services such as adult social care.
Mr Cameron said he accepted all councils were having to "do more with less" due to the tough financial climate and that Liverpool had higher levels of economic and social deprivation than many other areas.
But he said the statistics did not back up claims that Liverpool and other cities in the North West were bearing the brunt of the cuts.
"Is Liverpool being unfairly treated this year? I don't believe it is," he said.
Liverpool City Council was spending £21.7m more than last year, he said, while spending per household in Liverpool, would be £2,595 in 2014-15, compared with £1,874 per dwelling in west Oxfordshire, where he is an MP.
"It is important to make this point to show how fairly we manage things. Liverpool gets extra provision compared to the average."
"I am proud to be prime minister of a country that generously supports areas which have greater needs."
He added: "Spending power in Liverpool, a combination of council tax, grant and the money you get from business rates, is being reduced by 1.3% in 2013.
"That is absolutely the same as the average English reduction, which is 1.3%."
In a recent report, the local government spending watchdog said the majority of councils had coped well with the squeeze on their finances since 2010, by making efficiencies and reducing staff numbers, but warned things could get tougher.
Local Government Secretary Eric Pickles has urged councils with financial worries to dip into their reserves, money set aside for specific purposes and emergencies.
The prime minister said Liverpool was "adding to its (financial) reserves while making these complaints not drawing on its reserves".
"If Liverpool city councillors are saying this funding is so unfair, why are they choosing to add reserves this year rather drawing on these reserves?
"They are being added to, not used."
More broadly, he said the economy in the north-west of England was improving, with unemployment down and business creation up but he admitted it would take time to recover from the worst recession for decades.
In an article for the Liverpool Echo, Mr Anderson said that "when Mr Cameron comes to praise Liverpool, he also plans on stabbing us in the back".
He told the BBC he was offering ministers the opportunity to look at the city's finances in an "open and transparent" way.
"We have made a request to you and Mr Pickles to visit Liverpool to see if we are scaremongering and creating political mischief, as has been suggested by him.
"We are not lying about it. We are just asking for fairness."
In response, Mr Cameron said he and his ministers visited the city regularly.


Manchester United manager Jose Mourinho wants £89m Paul Pogba to not worry about his world record transfer fee.

France midfielder Pogba has not scored or set up a goal in four games since his summer return to Old Trafford from Italian champions Juventus.
However, Mourinho says he is "full of trust" in the 23-year-old and insists his performances will improve.
"The world-record player is always a question, but I want Paul to forget that," said the Portuguese.
"He played in the Euro 2016 final, went on holiday, then had no pre-season. It is normal after the first game he has a little decrease.
"I am full of trust because I know he is a good guy with a lot of ambition, so the form will come naturally."
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Meanwhile, Pogba's team-mate Ander Herrera has described Mourinho as the "perfect" manager for the club.
United have lost their past two matches against Manchester City in the Premier League and Feyenoord in the Europa League, and defeat at Watford on Sunday would mark the team's worst run since December.
But Herrera said: "Players like Pogba and Zlatan Ibrahimovic came partly because this is a massive club - but also because Mourinho is here.
"His way of thinking is what this club wants.
"If you are an honest player, he is going to be an honest manager with you."
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When I started first reporting on pollution in London, many moons ago, the real concern was particulate matter - the tiny particles mainly from traffic - that can cause health problems.

We still have episodes of high particulates in London - there was one a few weeks ago compounded by high levels of wood burning.
The focus now though is nitrogen dioxide (NO2) mainly from diesel engines and how that can be reduced.
London Mayor Sadiq Khan estimates thousands of Londoners every year have their lives shortened by pollution.
Ironically, London is probably at the forefront of anti-pollution policy.
We have had a low emission zone for many years and have tried green walls and dust suppressants for example, with limited success. But the capital still breaches pollution limits.
The current mayor is introducing a toxicity charge for central London and expanding an ultra low emission zone.
9,400
Premature deaths a year in London linked to air pollution
500,000 aged under 19 who live in areas that breach EU limits
443 schools that have unsafe pollution levels
86 of these are secondary
2025 year London is expected to meet EU limits
Pollution is also now very prominent in the minds' of the public - for one thing, it receives a lot more publicity than it used to.
The response to a recent mayoral consultation on pollution was the highest ever.
Environmental lawyers like ClientEarth and campaigners like Clean Air for London are organised and efficient at highlighting the problem.
And while many ideas are touted to reduce pollution, the real solution, clean air campaigners will tell you, is to reduce emissions and even ban diesels.
But something interesting is happening in the wider court of public opinion. Changes are happening in the vehicle market.
Is the drip, drip of health warnings, and talk of policy initiatives - like the ultra low emission zone, and stories like the VW emissions scandal, having an effect?
Yesterday, it was announced the sales of diesel cars dropped 9.2% compared to a year ago. That was combined with a record 48.9% increase in electric cars and other alternatively-fuelled vehicles.
And while this is not a pollution solution, drivers' behaviour is changing and it seems diesel is in decline.


A Moray primary school has been forced to close for a deep clean after 53 children and staff were recorded sick.

Tomintoul Primary only has 40 pupils enrolled in the school, but many have been hit with the sickness bug.
Moray Council said the deep clean was a precautionary measure, and there was no reason to believe the school was the cause of the outbreak.
It said it was following NHS guidelines. The school will be closed all day Thursday as a result.


Eight people were taken to hospital after two trains crashed in Norfolk.

The collision happened on Norwich station's platform six at about 00:10 BST.
The Greater Anglia Great Yarmouth to Norwich service and a stationary East Midlands Trains unit were involved in the "low speed" collision.
The ambulance service said all eight people - including four who were stretchered away - had minor injuries.
The two trains remained upright after the crash.
Both the Rail Accident Investigation Branch and British Transport Police are investigating the collision.
Police said the Great Anglia service was travelling at about 10mph when it collided with the second train.
A spokeswoman for East Midlands Trains said its train, which was empty at the time, has been removed from service because of the damage caused.
"Our first thoughts are for the welfare of those who have been injured in the incident," she said.
A spokeswoman for Greater Anglia said: "The train arriving at Norwich was travelling at very slow speed.
"There were 31 passengers on board.
"Our first priority has been and remains the welfare of the passengers and train crew involved."
The injured were taken to the Norfolk and Norwich Hospital and later discharged.


Oldham Athletic midfielder Paul Green has signed a new one-year contract with the League One side.

The 34-year-old joined the Latics from Rotherham last summer and featured in 47 games in 2016-17, scoring once.
He has also played for Leeds United, Derby County and Doncaster Rovers, as well as a loan spell at Ipswich Town.
Green follows defender George Edmundson and full-back Brian Wilson, who have both signed new deals with Oldham in the past week.


In late October 2016, the residents of the tiny Bahamas island of Man-O-War Cay found a mysterious object had washed up on their beach.

Taller than a person, conical in shape with a large spike at the end, it looked unmistakably like some sort of missile.
"People were curious of course, the kids were excited to see something so large on the beach," local resident Mailin Sands told the BBC.
It had washed up right in front of the holiday home of Prof Janine Maddock, who was back in the US at the time and spied it from a CCTV camera at the top of her house.
"I got an email from a local person - saying look what's rushed up in front of our beach," she said.
From pictures she was sent, Prof Maddock identified it as the nose cap section of a Trident II D5 missile.
She told the BBC about the story after hearing the news of a reported misfire of a UK Trident missile last June.
Prof Maddock initially thought it may have come from the UK missile, although the US Navy confirmed the object had come from one of their tests.
She initially hoped the islanders could keep hold of the nose cap.
"We have a local museum and I wanted to put it there with other weird stuff that washes up on our beach or I thought it could go on the top of our gazebo.
"Kids started playing on it. People were concerned about it so I contacted the navy."
The US Navy said it was the "nose fairing of a Trident II missile from a recent US missile test" and on 7 November a US Coast Guard helicopter took it away.
The nose cap washing ashore may have been an unusual sight but it is not the sign of anything going wrong.
In fact, the nose cap is designed to fall off as part of the flight of the missile and does so very early on in the process.
Many Trident tests take place off the Florida coast on the Eastern Test Range, which is not far from the Bahamas.
A US defence official told the BBC: "That nose fairing, it's not from the UK mission. It came from a US fired missile.
"When a missile flies - the fairing ejects from the missile. It is part of the process and it falls safely into the sea.
"In the simplest of terms, they serve as protected covering for a missile and at a certain point it's no longer needed.
"Generally speaking the nose fairing is nowhere near the location of final impact. It comes off far sooner in process."
Britain's nuclear weapons system is completely reliant on the United States.
The missiles are produced and serviced by the US.
Britain has purchased the right to 58 missiles from a common pool held at the US Strategic Weapons Facility in Kings Bay, Georgia.
The US also runs everything to do with the testing - from when it's fired off the Florida coast, to the satellites in space to follow the trajectory and all the way to the Ascension Islands where the US can monitor the missiles re-entry and splash down.
David Russell was the Commander of the HMS Vanguard until 1994 and carried out the first Royal Navy Trident test in 1994 on the Eastern Test Range.
"Firing the missile is the last element of a very long training process. It's called a DASO (Demonstration and Shake Down operation)," he said.
"The DASO period is one of shore-based training and equipment certification first and then at sea training and eventually the firing itself.
"From memory, it takes two to three weeks for each crew but, of course, it comes at the end of a long and intensive training period, (known as work-up), for the submarine and crew following a full refit in dock, so it is the final step in the process of becoming fully operational."


Government-allied youth in Burundi have gang-raped women and girls whose male relatives are suspected to be opposition activists, campaign group Human Rights Watch (HRW) has said.

Some of them were tied up and raped at gun or knife point, as their families and children watched, it added.
HRW blamed most of the rapes on Imbonerakure, the youth wing of the ruling party, and the security forces.
Burundi's government described the allegations as "falsehoods".
Imbonerakure played a key role in helping President Pierre Nkurunziza remain in power following his decision in April 2015 to seek re-election.
He survived a coup attempt and mass protests and won subsequent elections.
At least 439 people were killed and 240,000 fled to neighbouring states during the unrest, according to the UN.
HRW said that 323 cases of rape or sexual assault, affecting 264 women and 59 girls, were reported from May to September 2015.
It has interviewed more than 70 survivors who have fled to a refugee camp in Tanzania.
"In a pattern of abuse in many locations and in several provinces, men armed with guns, sticks, or knives have raped women during attacks on their homes, most often at night," HRW said in a report.
"Many of the women have suffered long-term physical and psychological consequences," it added.
HRW quoted a 36-year-old survivor as saying: "I was held by the arms and legs. [An attacker] said: 'Let's kill her, she is an [opposition National Liberation Forces] FNL wife' as they raped me."
Other rape cases documented by HRW included:
"Women said that if the man wanted by the attackers was not there, they would demand to know his whereabouts and would sometimes tell the victim that they were raping her because they could not find the man," HRW said.
"In nine cases, women said the men had fled before the rape took place, or had begun habitually sleeping elsewhere because of threats," it added.
Presidential spokesman Willy Nyamitwe said HRW had damaged its credibility through the "publication of falsehoods".
"Imbonerakure is not a gang of rapists," he added.


Although most of Nigeria's current population of about 170 million was not born when the country's first coup was staged 50 years ago, its legacy lingers on, writes Nigerian historian and author Max Siollun.

On 15 January 1966, a group of young, idealistic, UK-trained army majors overthrew Nigeria's democratic government in a violent military coup.
The coup leaders described it as a brief and temporary revolution to end corruption and ethnic rivalry. Instead, it made them worse.
The coup exposed the vulnerability of the Nigerian state, and how simple it was to use soldiers to attack the government, rather than protect it.
A succession of increasingly repressive military governments ruled Nigeria for 29 of the next 33 years, until the restoration of democracy in 1999.  Here are four ways in which Nigeria - Africa's most populous state and leading oil producer - is still affected by the events of 1966:
Biafra protests
Protesters in south-east Nigeria have recently demanded the region's secession from Nigeria and the formation of a new country called Biafra. The Biafra movement's origins can be traced back to the January 1966 coup.
The officers who staged the coup were mostly Christian southerners from the Igbo ethnic group, and they assassinated several northerners, including the four highest-ranking northern army officers, Prime Minister Tafawa Balewa, and Northern Region Premier Ahmadu Bello (both Muslims from the north).
Army commander Major-General Johnson Aguiyi-Ironsi, an Igbo, suppressed the coup, but seized power himself. Northerners interpreted the coup as an Igbo-led conspiracy to subjugate the north and impose Igbo domination.
Six months later, northern soldiers staged another even bloodier counter-coup against their Igbo colleagues.
Northern mobs killed around 30,000 Igbos, and Igbos fled south, and in the following year sought to form a new breakaway country called Biafra. Northerners living in Igbo areas were also killed in revenge attacks.
Although the army suppressed the attempt at secession after a brutal civil war, bitterness remains 50 years later.
Unaddressed grievances from 1966 lie at the heart of the Biafra movement's resurgence. Many Igbos feel that Nigeria regards them as a fifth column and is still punishing them for their previous attempt at secession.
Corruption
One of the coup leaders Major Nzeogwu said: "We wanted to get rid of rotten and corrupt ministersâ€¦ We wanted to gun down the bigwigs in our way."
His coup unwittingly entrenched the presence of "rotten and corrupt ministers". His best friend was a young western army officer named Major Olusegun Obasanjo.
Ten years later, he found himself at the head of a different military government. It promulgated a new constitution that gave the government ownership of all mineral resources.
This provision encouraged corruption and the do-or-die nature of Nigeria's elections, as winners now had control over the country's vast mineral wealth.
It is also the source of much bitterness in Nigeria's oil-producing areas, and a cause of the latent Niger Delta insurgency which rocked Nigeria for several years and severely disrupted its oil industry.
'Class of 1966'
The January 1966 coup propelled a group of young military officers onto the national stage. Now wealthy septuagenarian grandfathers, they still wield enormous influence in Nigerian politics.
Gen Obasanjo is one of these retired military kingmakers. His withdrawal of support for then-President Goodluck Jonathan was one factor in his presidential election defeat last year, and the victory of current President Muhammadu Buhari.
As a young officer, Mr Buhari was among the young northern officers who in July 1966 staged the counter-coup against the Igbo majors.
The influence of retired military officers is so pervasive that Mr Jonathan is the only president in Nigeria's history who had no personal or family involvement in the 1966 crisis and the ensuing civil war.
Ghosts of the past
The army's politicised past means that Nigerians live with the (real or imagined) fear that a coup is a possible outcome of any political crisis.
Last year, Nigeria's then-national security adviser admitted that previous governments' wariness of the coup-prone army made them reluctant to upgrade its weaponry.
Years of strategic military under-investment recently came back to haunt Nigeria when soldiers facing Islamist militant group Boko Haram complained that they were under-equipped to fight the insurgents.
This coup issue also partly explains why Nigerian authorities react with such severity to any disobedience by soldiers.
Surviving Boko Haram
Inside militant stronghold
Yet, ironically, Nigeria partially owes its continued existence to the near obsessive desire to avoid a repeat of the 1966 bloodshed.
The young military firebrands have mellowed and talk their way out of crisis rather than blasting their way into it.
The elaborate power-sharing arrangements in Nigeria's constitution, and the unwritten rule requiring rotation of political power between the north and south are legacies of the mistrust engendered in 1966.
Nigeria has matured. So have its former coup leaders.
* Max Siollun is a Nigerian historian, writer, and author of the books Oil, Politics and Violence: Nigeria's Military Coup Culture 1966-1976 and Soldiers of Fortune: a History of Nigeria (1983-1993).


Tottenham maintained their unbeaten start to the Premier League season with a comfortable victory against winless Sunderland at White Hart Lane.

Spurs dominated but did not make the breakthrough until Harry Kane scored with their 22nd attempt on goal.
Papy Djilobodji failed to clear a Dele Alli header allowing Kane to poke home from point-blank range on 59 minutes.
Late on, Kane suffered a nasty ankle injury and Sunderland's Adnan Januzaj was sent off for a second booking.
Relive Spurs's dominant display
A fourth defeat in five games means Sunderland are yet to win in the league under David Moyes.
The scoreline could have been worse for them but for outstanding goalkeeper Jordan Pickford, 22, who made a string of saves to keep his side in the game.
England striker Kane, who scored his second goal of the season, limped off the field after injuring his ankle with three minutes remaining and eventually left on a stretcher.
Aside from losing Kane, there was further injury worry for Spurs as England's Eric Dier and Belgium's Mousa Dembele were both substituted in the second half with what appeared to be hamstring injuries.
Moussa Sissoko was given his first start for Spurs since his £30m move on transfer deadline day and he joined Dembele and Victor Wanyama in a powerful midfield as Erik Lamela and Christian Eriksen dropped to the bench.
Tottenham completely dominated the game with 31 shots and 73.8% possession.
In the first half alone, they mustered 19 efforts with Kane, Son Heung-min and Toby Alderweireld going close.
Impressive South Korea winger Son was Spurs' best attacking force with five key passes and seven shots, though only two were on target.
The win was the perfect response after the disappointing midweek Champions League defeat by Monaco at Wembley and moves Spurs up to third in the table.
In contrast to the home side's dominance, Sunderland had just three shots in the first half.
The first came after 22 minutes as Jermain Defoe latched onto a long ball from Pickford but was unable to get his shot past Hugo Lloris.
Steven Pienaar had the best chance of the half just before the break as he met Januzaj's cross but his shot from six yards was cleared off the line by Kyle Walker.
The worry for the Black Cats is that striker Defoe managed just 13 touches in the match and only one of those came in Spurs' area.
Pickford had the most touches and his eight saves were vital in keeping the score respectable.
Moyes will have to do without Januzaj for the next match as the on-loan Manchester United winger was dismissed for a second booking in the space of 10 minutes. Having been cautioned for dissent, he saw red after fouling Ben Davies.
Sunderland manager David Moyes: "Steven Pienaar had a great chance and we probably need to score any chance we get.
"Jordan Pickford is going to be a very good keeper. He has a lot of work to do at the moment, more than I'd like him to get. He will get better, he has a real good future ahead of him.
"We had a chance to clear the ball for the goal. That was a mistake and, of all the chances Tottenham got, that was a soft one and we gifted them that.
"It is a big job. I know how much is going to get better. All we can do is keep getting on the training field and making it better and I enjoy doing that."
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Tottenham boss Mauricio Pochettino: "Sometimes it's difficult. In the end it was fair.
"We fought a lot and tried to score. I'm happy with the three points and it takes away the feeling from losing against Monaco.
"I want to create chances and play well - sometimes you need a lot of chances to score. Today we always tried to go forward. We feel disappointed because we created a lot of chances in the first half."
Tottenham host League One side Gillingham in the EFL Cup on Wednesday before travelling to Middlesbrough in the Premier League on Saturday.
Sunderland are at Championship side QPR in the EFL Cup on Wednesday before entertaining Crystal Palace in the Premier League on Saturday.
Match ends, Tottenham Hotspur 1, Sunderland 0.
Second Half ends, Tottenham Hotspur 1, Sunderland 0.
Attempt saved. Son Heung-Min (Tottenham Hotspur) left footed shot from the left side of the box is saved in the top left corner. Assisted by Erik Lamela.
Corner,  Tottenham Hotspur. Conceded by Lamine Koné.
Attempt missed. Dele Alli (Tottenham Hotspur) right footed shot from more than 35 yards misses to the left.
Substitution, Sunderland. Paddy McNair replaces Jason Denayer.
Attempt missed. Vincent Janssen (Tottenham Hotspur) left footed shot from outside the box is too high. Assisted by Erik Lamela.
Attempt blocked. Jermain Defoe (Sunderland) left footed shot from outside the box is blocked.
Attempt missed. Erik Lamela (Tottenham Hotspur) left footed shot from outside the box is too high from a direct free kick.
Papy Djilobodji (Sunderland) is shown the yellow card for a bad foul.
Vincent Janssen (Tottenham Hotspur) wins a free kick in the attacking half.
Foul by Papy Djilobodji (Sunderland).
Second yellow card to Adnan Januzaj (Sunderland) for a bad foul.
Ben Davies (Tottenham Hotspur) wins a free kick on the left wing.
Foul by Adnan Januzaj (Sunderland).
Attempt missed. Duncan Watmore (Sunderland) header from the centre of the box misses to the right. Assisted by Javier Manquillo with a cross.
Substitution, Tottenham Hotspur. Vincent Janssen replaces Harry Kane because of an injury.
Delay over. They are ready to continue.
Delay in match Harry Kane (Tottenham Hotspur) because of an injury.
Attempt missed. Erik Lamela (Tottenham Hotspur) left footed shot from the right side of the box is close, but misses to the left. Assisted by Dele Alli.
Ben Davies (Tottenham Hotspur) is shown the yellow card.
Foul by Moussa Sissoko (Tottenham Hotspur).
Adnan Januzaj (Sunderland) wins a free kick on the right wing.
Corner,  Tottenham Hotspur. Conceded by Papy Djilobodji.
Attempt blocked. Erik Lamela (Tottenham Hotspur) left footed shot from the right side of the box is blocked. Assisted by Harry Kane.
Adnan Januzaj (Sunderland) is shown the yellow card.
Corner,  Tottenham Hotspur. Conceded by Duncan Watmore.
Substitution, Sunderland. Wahbi Khazri replaces Jan Kirchhoff.
Dele Alli (Tottenham Hotspur) wins a free kick in the defensive half.
Foul by Didier Ndong (Sunderland).
Substitution, Tottenham Hotspur. Ben Davies replaces Eric Dier because of an injury.
Substitution, Tottenham Hotspur. Erik Lamela replaces Mousa Dembélé because of an injury.
Delay over. They are ready to continue.
Delay in match Mousa Dembélé (Tottenham Hotspur) because of an injury.
Attempt missed. Eric Dier (Tottenham Hotspur) right footed shot from the centre of the box is close, but misses to the left following a corner.
Corner,  Tottenham Hotspur. Conceded by Jordan Pickford.
Attempt saved. Dele Alli (Tottenham Hotspur) right footed shot from outside the box is saved in the bottom right corner. Assisted by Mousa Dembélé.
Attempt missed. Moussa Sissoko (Tottenham Hotspur) right footed shot from outside the box misses to the left. Assisted by Harry Kane.
Attempt missed. Lamine Koné (Sunderland) header from the centre of the box is too high. Assisted by Adnan Januzaj with a cross following a corner.
Corner,  Sunderland. Conceded by Kyle Walker.


More than £10m has been secured to restore an iconic university college in Ceredigion.

The National Lottery support for Aberystwyth University's Old College was announced on Wednesday.
It comes as part of a £22m plan to turn the Grade I-listed building into a centre for heritage, learning and enterprise.
It is hoped the work will be completed in time for the university's 150th anniversary in 2022.
A performance and gallery space will be created for artists, exhibitions and musicians and there will be a centre for entrepreneurs and new businesses, a cafe and community rooms.
The college will also house a university museum, allowing some of the 20,000 items normally in storage to be shown.
A new science centre will showcase interactive displays alongside a planetarium and 4D facility, highlighting the university's links with the European Space Agency.
The college was bought in 1867 by the University of Wales for just £10,000, using money donated by the community.
It first opened its doors to students in 1872 - before focus shifted in the 1960s when the university moved to a new campus.
John Glen MP, announcing the funding, said it was "recognised as one of the UK's most significant pieces of Gothic revival architecture".
The university is still looking at ways to raise additional funds, including a major appeal.
Ceredigion MP Ben Lake said: "This is great news for Ceredigion and will reveal the hidden history of an iconic landmark as well as paving the way for its future.
"The Old College will once again be recognised as a beacon of culture and creativity, and a major catalyst for economic and social regeneration."


Two bottles of whisky recovered from a shipwreck that inspired the book Whisky Galore may have been missed from official statistics.

The cargo ship SS Politician, which had 28,000 cases of whisky, sank off Eriskay in Western Isles 75 years ago.
Eight bottles of the whisky were recovered by a diver in 1987.
The National Trust for Scotland (NTS) has suggested that two bottles it has on the Isle of Canna could be added to these eight known bottles.
The bottles in the care of NTS are kept at Canna House and belonged the late John Lorne-Campbell and his wife Margaret Faye-Shaw, who gifted the property and Hebridean island to the trust.
Fiona McKenzie, archivist at Canna House, said: "According to the previous archivist, the bottles have 'always been at the house'.
"She was here from the 1960s and that's well before the diver brought up eight bottles in 1987. So looks like we may have two bottles that are not included in the official stats."
Many other bottles were salvaged from the SS Politician at the time of its sinking in 1941 and still thought to survive, but have not been officially recorded.
Hundreds of cases of whisky were hidden from customs officers by islanders. Some locations of these secret stashes have since been forgotten, according to islanders today.
The SS Politician was headed for Jamaica when it ran aground on the northern side of Eriskay in bad weather.
Scottish author Compton Mackenzie, published the novel Whisky Galore in 1947, which was loosely based on the shipwreck.
It was adapted for the cinema in a 1949 Ealing comedy.


The number of people getting married in England and Wales fell in 2013 for the first time since 2009, according to the Office for National Statistics (ONS).

There were 240,854 marriages in 2013, a drop of some 8.6% compared with 2012, the ONS said.
Elizabeth McLaren, ONS statistician, said the fall could be the continuation of the decline in marriages since 1972.
It could also be due to superstitious couples choosing to postpone to avoid the number 13, she said.
Religious ceremonies decreased by 14%, while civil ceremonies declined by 6% in 2013, compared with 2012.
Civil ceremonies accounted for 72% of all marriages in 2013.
Ms McLaren said that, unlike other milestones in life such as births and deaths, people have absolute control over when they tie the knot.
"When you have the freedom to choose there are probably certain dates you might avoid, like Friday 13th and that sort of thing," she said.
"It is going to be interesting to see whether this is part of a long-term decline or if it will change again."
Holly Tootill, a family lawyer with JMW Solicitors, agreed that superstition might have played a part in the decrease in the number of couples choosing to marry during 2013
"I personally know of several individuals who had consciously decided to marry a year later rather than risk going against the grain of superstition.
"In my experience, it's not unusual for luck, fortune and omens to feature in how couples divorce as well as wed although I have to say that such matters are generally not considered priorities for the majority of people choosing to spend the rest of their lives together."
Newlyweds are also continuing to get older, with men a mean age of 36.7 when they walk down the aisle and women are on average 34.3 years old.
And there has been a rise in marriages among pensioners, fuelled by women getting married in their later years.
In the decade since 2003 there has been a 33% increase in the marriage rate for women aged 65 and over, bucking the overall trend of decline.
The marriage rate for men aged 65 and over only rose by 2% over the same period.
Marriages of same sex couples first took place on 29 March 2014, so were not included in the statistics.


The family of a 30-year-old man whose body was discovered in a house in West Lothian have paid tribute to a "much-loved son, brother, father and uncle."

Terry Miller's body was found in the property in Whitburn's West Main Street on Tuesday.
Bertie Hall, 49, appeared at Livingston Sheriff Court on Thursday charged with Mr Miller's murder.
In a statement issued through Police Scotland, Mr Miller's family said he would be "greatly missed."
They said: "We would like to thank everyone for their kind thoughts at this difficult time but would now ask for privacy to come to terms with our loss."


Delegates at a UN climate conference in Paris have approved a draft text they hope will form the basis of an agreement to curb global carbon emissions.

The 48-page document will be discussed by ministers on Monday.
They will try to arrive at a comprehensive settlement by the end of next week.
The French climate ambassador warned that major political differences still needed to be resolved.
Delegates from 195 countries worked through the night at the conference centre in Le Bourget, conscious of a midday Saturday deadline imposed by the French presidency of this meeting.
The weighty document will now go forward to ministers who will have to take the many political decisions still required, if the text is to be turned into a long-term agreement.
"Nothing has been decided and nothing will be left behind," said French climate ambassador Laurence Tubiana.
"This text marks the will of all to reach an agreement. We are not at the end of the route. Major political issues are yet to be resolved," she warned.
Many delegates were relieved that they had at least reached this point, as it marks a critical point after four years of negotiations.
The document lays out a range of options for ministers on what the long-term goal of the deal should be, as well as the scale and the methods of raising climate finance for poorer nations.
Among the many tricky issues they will have to deal with is differentiation: many countries are reluctant to change the way that nations are divided into developed and developing, based on where they were in 1992, when the UN Convention was signed.
Many richer countries want this to change, and want a greater number of emerging economies to take on emissions reduction targets and become climate finance donors.
South Africa's climate ambassador struck a note of warning on this issue.
"The Paris outcome must be under the convention and in accordance with its principles and provisions and must not rewrite or re-interpret its decisions," said Nozipho Mxakato-Diseko, who speaks on behalf of more than 130 developing nations.
Negotiators had hoped to be much further forward at the end of the week. They started out with a 50-page document and by Friday had reduced it to 36 pages of text.
"We now need to summon the political will needed to make the hard decisions required for an effective and durable agreement that protects the most vulnerable among us," said Thoriq Ibrahim of the Maldives and Chair of the Alliance of Small Island States.
Many countries had reservations about the Friday document, so what has now been agreed contains these concerns added as an annex - pushing the document to 48 pages.
There are worries that far too much has been left to ministers to agree, and that in an effort to reach a deal, too many compromises will be made.
"We're hoping that in the rush to the end, ministers do not trade ambition for expediency, and remain true to the science," warned Tasneem Essop from WWF.
Follow Matt on Twitter @mattmcgrathbbc.
COP 21 - the 21st session of the Conference of the Parties - will see more than 190 nations gather in Paris to discuss a possible new global agreement on climate change, aimed at reducing greenhouse gas emissions to avoid the threat of dangerous warming due to human activities.
Explained: What is climate change?
In video: Why does the Paris conference matter?
Analysis: Latest from BBC environment correspondent Matt McGrath
More: BBC News climate change special report


A new forensic and biometrics service is planned by the Home Office, four years after it controversially abolished its predecessor.

Ministers say there will be a "national approach" to forensic science in criminal cases in England and Wales.
The Forensic Science Service, a government-owned company, was shut down in 2012, after the government said it lost Â£2m each month.
But in 2015, the National Audit Office warned standards were slipping.
It said forensic science provision was under threat because police were increasingly relying on unregulated experts to examine samples from suspects and crime scenes.
The spending watchdog's report came after work was transferred to in-house police labs and private firms.
Senior politicians, scientists and lawyers had warned in 2012 that closing the forensic science archive would cause miscarriages of justice and stop police solving crimes, as police forces had to create individual storage systems.
In its plan, the Home Office acknowledged forensic science provision had become fragmented.
Digital analysis of computers and smart-phones was being conducted in an "ad hoc manner" which did not provide value for money, it said.
Ministers said they were supporting a police review of whether there should be a "joint Forensic and Biometric Service" to achieve economies of scale, increased capability and resilience.


The former police chief who set up Operation Sanctuary said she was "kept in the dark" about the use of a convicted child rapist as an informant.

Sue Sim, who retired in 2015, said she was appalled and would never have agreed to his use or the payment.
Information provided by the man, known as XY, led to the conviction of 17 men and one woman for abusing girls in Newcastle, Northumbria police claimed
The force said it was inappropriate to comment on individuals' opinions.
It emerged during the court processes that XY was paid £10,300.
The current chief constable, Steve Ashman, has defended the move, saying he was "certain as I can be" that it was "morally" right.
"What we've ended up doing here is putting dangerous men behind bars and protecting vulnerable women and girls that we simply wouldn't have been able to do if we didn't have that jump off point we got [from the information]," he said.
The use of XY was "inside the law and inside accepted policy and practice", he added.
However, Ms Sim, who following her retirement made allegations about sexism within the force, has called for a public inquiry.
She said: "I created this operation and I'm delighted at the success of it, in that 18 people who should be off the streets, are now off the streets.
"But I'm very, very surprised at this as a tactic. I'm absolutely horrified, appalled.
"I would never have agreed to the payment of a convicted child rapist.
"I keep hearing it was a very difficult decision - clearly it was so difficult that they didn't tell me. Probably because they knew I would totally and utterly disagree."
There were a number of overt and covert tactics which could have been put in place, she said.
"The big issue with this one is, I haven't read anything, I haven't heard anything in the news, that actually says what evidence was actually produced by this informant?
"Two wrongs don't make a right - he was a convicted child rapist and you can never put sufficient safeguards in place."
She added: "The success of the operation should not be tarnished by this, but it does need further serious investigation.
"I feel so passionately about this that I would like to apologise to any rape victims who feel they have been let down by this."
Northumbria Police said in a statement it had been "open and transparent" in its response to Operation Sanctuary and the use of XY, but it "wouldn't be appropriate" to comment on individuals' opinions.


Tributes are pouring in for the leader of Hastings Council who died after suffering a stroke at the age of 63.

Jeremy Birch had been a member of the council since 1998 and led it for 13 years, over two separate periods.
A book of condolence has been opened in the Town Hall and a flag is being flown at half mast as a mark of respect.
Peter Chowney, of Hastings Council, described his friend as "a tireless fighter for what was right and good". He added: "I can't believe he is gone."
The Labour councillor was taken to hospital after falling ill last week and was placed in a medically-induced coma.
On Wednesday, Mr Birch's partner issued announced his death.
A minute's silence was held during the election count on Thursday, the council said.
Deputy Leader Peter Chowney has taken over Mr Birch's duties. A personal friend of Mr Birch, he has spoken of his "enormous sadness".
He added: "My thoughts are with his partner Louise and his family at this terrible time."
Councillor Chowney said Mr Birch had dedicated his life to the borough's regeneration. He praised his "unswerving devotion to the place he was born in".
In a message to his friend, he added: "Goodbye Jeremy - you were a worthy son of Hastings, a tireless fighter for what was right and good, and a true socialist. We'll never forget you."
Hastings & Rye Labour Councillor Sarah Owen also paid tribute to a "friend and inspiration". She added: "We will all miss him deeply."
The Mayor of Hastings, Councillor Bruce Dowling, said he had lost "a real friend" and was "personally devastated".
He added: "Our meetings, Hastings Borough Council, and Hastings the town, will not be the same."


County champions Middlesex ended their winless start to the year by beating 2016 title rivals Yorkshire by an innings and 64 runs at Lord's.

The Tykes added only 22 runs to their overnight score to end their first innings 208 all out, 238 runs behind.
Following on, Adam Lyth, Alex Lees and Harry Brook then all fell in the space of nine balls to leave Yorkshire 16-3.
The visitors, beaten by Middlesex on the final day last season, were 174 all out for their first loss since April.
Adil Rashid (35) and Steven Patterson (30 not out) were the only two batsmen to make 30 or more in an uncharacteristically poor Yorkshire display.
Five different Middlesex bowlers chipped in with second-innings wickets, with seamers Tim Murtagh and Toby Roland-Jones taking two each and spinner Ollie Rayner returning figures of 4-35.
Sam Robson's 159 and 111 from Paul Stirling on the opening day had set the platform for the hosts, who had won only two of their 13 previous games across all formats this season.
Middlesex captain James Franklin told BBC Radio London:
"We have bounced back strongly after getting a bit of a towelling from Lancashire at Southport last week. It was really important that we fronted up here. To beat Yorkshire inside three days is very satisfying.
"Our bowlers asked some serious questions of Yorkshire's batsmen and, when you got it in the right areas, it was a tough pitch to bat on as it deteriorated.
"Sam Robson and Paul Stirling batted brilliantly to set the match up for us on the first day with their hundreds, and we backed that up beautifully with the ball."
Yorkshire head coach Andrew Gale told BBC Radio Leeds:
"First day, bowling wise, we did quite well without a lot of reward. That was when the pitch was at its best. We got rewarded for that second morning.
"But, from then on we were well below par. From a batting point of view, we were well below par. We had a long chat and some strong words about the batting at Taunton (against Somerset) and some more strong words in this game.
"We expect a response. As well as we bowled, Middlesex were up for the challenge and were a lot more patient than us. To be bowled out twice like we have is poor."


The price of Bitcoin, a digital currency once located at the fringe of finance, has been rising to new records in recent months as digital assets move into the mainstream.

On Tuesday, it shot past $2,200 (Â£1,700), more than doubling from just two months ago. And a newer currency, Ethereum, has climbed even faster.
Industry members say uncertainty surrounding the value of global currencies, including the pound, is driving demand for alternative currencies.
The kind of technology that underwrites Bitcoin and newer entrants such as Ethereum, is also gaining, well, currency, as it gets put to new uses by developers and others looking to beef up cyber-security.
Policy changes in Japan and elsewhere in Asia have made it easier to trade. And of course, when it comes to price, interest generates its own momentum.
"It's a promising technology," says Joshua Rosenblatt, 34, a Nashville-based attorney at Frost Brown Todd, a midwestern law firm with offices in eight states. He is both an investor and works in the field. "The returns have been unreal and there's an aspect of not wanting to miss out on a bubble."
Bitcoin's market capitalisation shot past $30bn this month, as the price climbed.
Ethereum remains smaller at about $15bn, but it is growing too. The price spiked from less than $20 in March to about $170 today, according to CoinDesk, which tracks the two currencies.
Activity is also up. The number of daily trades in Bitcoin, which is more established, has rocketed from around 40,000 at the start of 2013 to more than 330,000 today.
About 2,700 participants attended an industry conference in New York this week, according to Michael Crosby, head of strategy for CoinDesk, which hosted the event.
Mr Rosenblatt, one of the people in attendance, works with smaller investment firms and start-ups, navigating issues relating to coin offerings and "smart contracts", which use similar technology to enforce and verify business transactions.
In the last year, the number of clients looking for that work has increased from one to about two dozen, he says.
"Our firm is kind of a middle America firm, so the fact that we're seeing that sort of interest speaks to how much the industry has grown," he says.
Grayscale launched its first digital currency investment trust in 2013.
The New York firm now manages about $400m of investments in digital currencies, up from $60m at the end of 2015, as its client base of wealthy investors, hedge funds and other small firms has grown, and prices for Ethereum and Bitcoin have climbed.
"We've seen just an absolute explosion," says Matthew Beck, an associate at the firm.
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Mr Beck says the firm expects to continue to attract interest, as investors use digital assets to diversify.
"We're seeing investors start to diversify... and carve out an allocation for digital assets," he says.
At the moment Bitcoin is used for cross-border transfers, payments for online activities such as gaming and gambling - and as an investment, says Peter Smith, chief executive of Blockchain, one of the major trading platforms.
The currency also made headlines as the preferred currency of the hackers behind the recent attack that crippled the National Health Service in the UK and other organisations around the world.
Industry members say some companies may be buying up Bitcoin to deploy in the event of a future attack, but they maintained that broader demand is driving price gains.
"There's a number of people from family offices [and] private equity firms - they're making small bets and when you add that type of liquidity to the market, that's going to drive the price up," says Mr Crosby.
This year's Consensus conference drew some big corporate names, such as insurer State Farm, carmaker Toyota, and consulting firm Deloitte.
Fidelity Investments, a staid, Boston-based money manager known for handling retirement accounts, was one of the presenters. It now accepts Bitcoin in its cafeteria and will soon launch a feature to allow clients to check on their digital currency holdings alongside other investments.
In the scheme of global finance, a $30bn market remains "trivial", says Blockchain's Peter Smith. But interest from those players is a sign the industry is becoming more accepted.
"It has truthfully gotten a lot more mainstream and that's a beautiful thing to see in many ways," he says.
For 49-year-old Stuart Fraser, the climbing price has meant a tidy return on the roughly Â£15,000 worth of Bitcoin he bought in early 2014.
He estimates his holdings have more than doubled, even after subtracting the Bitcoin he used to buy a virtual reality headset and make investments in the newer Ethereum.
Investors say they are prepared for a boom-bust cycle as the market continues to evolve, technology changes, and regulations come into play.
But Mr Fraser, the managing director of Scotland-based financial technology start-up Wallet.Services, who previously worked in cyber-security, says unless he sees a promising new competitor, he doesn't plan to cash in now.
"I think [in the] long term, it's going to go up."


Bristol's director of rugby Andy Robinson insists there has been no approach from the Rugby Football Union for coach Steve Borthwick.

There have been reports linking the 36-year-old with a role under new England head coach Eddie Jones.
The Australian, who agreed a four-year deal last week, coached Japan during the World Cup, with ex-England captain Borthwick as one of his assistants.
"There has been no contact from the RFU," Robinson told BBC Radio Bristol.
"It is very simple for us: Steve Borthwick is employed by Bristol Rugby.
"He is here for two years and his focus is on Bristol Rugby getting promotion."
Borthwick's relationship with Jones goes back to their time together at Saracens, with the former lock skippering the team during Jones' second season as head coach at the club.
He retired in 2014 and was recruited by Bristol as their forwards coach last month.


A former Cheshire salt works has reopened to the public as a museum after a £10.2m restoration.

The Grade II-listed Lion Salt Works, near Northwich, produced salt since its opening in 1894 but closed in 1986.
A four-year project used traditional construction skills and most of the original building material, Cheshire West and Chester Council said.
It added the museum, which also has a butterfly conservation area, aims to be "a valued resource" locally.
The restoration received a £5.3m grant from the Heritage Lottery Fund and £3m from the site's current owners Cheshire West and Chester Council.
Lion Salt Works also featured on the BBC's Restoration programme in 2004, attracting more than 32,000 votes, but missed out on a place in the competition's final.
It is one of four historic open-pan salt-making sites in the world.
Source: Cheshire West and Chester Council


A man accused of the murder of a grandmother who was beheaded in London has been remanded in custody.

Nicholas Salvador, of Gilda Avenue, Enfield, is accused of killing Palmira Silva, 82, who was found in a garden in Edmonton, north London, on Thursday.
The 25-year-old is also charged with assaulting a police officer.
A post-mortem examination on Saturday found Ms Silva died from stab wounds to the heart and aorta. She was found decapitated, it is understood.
Mr Salvador was remanded in custody during a hearing at Highbury Corner Magistrates' Court and is due to appear at the Old Bailey on Tuesday.
The defendant was taken to the dock in the magistrates' court by four police officers, the BBC's Sophie Long said.
She said one officer had to confirm Mr Salvador's name to the court as he would not answer.
Police found Ms Silva's body behind a property, in Nightingale Road, after being called to the area following reports an animal had been attacked.
Officers evacuated nearby homes before the suspect was Tasered.
Neighbours described Ms Silva as a "lovely lady" and said she was an Italian widow who ran a cafe in Church Street, near Edmonton Green station.


Japanese carmaker Toyota has said it will recall 6.5 million vehicles globally over a faulty window switch.

The power switch could short-circuit, causing parts to overheat and potentially leading to a fire, the company said.
It is the latest in a string of recalls by the carmaker.
Toyota has already recalled some 10 million cars globally that were fitted with faulty air bags linked to a number of deaths.
The defective window switch affects models including the Yaris model as well as the Corolla, Camry, RAV4, Highlander and others.
The recall only affects cars produced between 2005 and 2010.
Of the total, about 2.7 million cars were sold in North America, 1.2 million in Europe, and 600,000 in Japan, the company said.
The firm explained that modules in a switch related to the electric window might have been lubricated inconsistently during manufacturing.
Debris caused by wear from the electrical contact points can accumulate and cause a short-circuit.
This could in turn cause the switch to overheat and melt, potentially leading to a fire.
Toyota said it was not aware of any accidents caused by the glitch.