Rafael Nadal will be the new world number one from next Monday after Roger Federer withdrew from the Cincinnati Masters with a back injury.

The Swiss 19-time Grand Slam winner was the only player who could have denied Spain's Nadal taking the top spot in the rankings from Andy Murray.
Federer was injured in Sunday's Rogers Cup final defeat by Alexander Zverev.
Briton Murray pulled out of Cincinnati last week as he continues to recover from a hip problem.
Reigning French Open champion Nadal returns to the top of the rankings for the first time since July 2014.
The 31-year-old went out of the Rogers Cup in the last 16 against wildcard Denis Shapovalov.
Federer went all the way to the final before losing to 20-year-old German Zverev in Montreal - the Swiss' first tournament since winning Wimbledon for the eighth time in July.
"I am very sorry to pull out," said the world number three. "Cincinnati has some of the best fans in the world and I am sorry I will miss them.
"Unfortunately, I tweaked my back in Montreal and I need to rest this week."
The Cincinnati Master leads up to the the US Open, the final Grand Slam of the year, which begins on 28 August.
Federer, 36, joins fellow top 10 players Murray, Kei Nishikori and Marin Cilic in withdrawing, while 2016 US Open winner Stan Wawrinka and 12-time Grand Slam champion Novak Djokovic will miss the rest of the season.


New trains, modern stations and affordable, simple tickets should be among the priorities for the next Wales and Borders rail franchise, an assembly report has said.

Four groups are bidding to run services from October 2018, with the decision in the Welsh Government's hands.
The economy committee said ministers faced a "heroically ambitious" task with no experience to fall back on.
Ministers said they wanted a transport network "fit for modern Wales".
AMs said passengers wanted punctual and reliable services with seats for all.
Those findings came in a survey of almost 3,000 rail users carried out as part of the committee's inquiry.
Its report, published on Friday, set out 10 priorities for the new Wales and Borders franchise:
Russell George, the Conservative AM who chairs the committee, said: "Awarding a rail franchise is not simple.
"So for the Welsh Government to be letting a franchise for the first time represents a big challenge. With no experience to fall back on it is doing everything from scratch. That alone would be cause for pause.
"But other circumstances - including the delays over the devolution of powers to the Welsh Government, uncertainty about funding, and the ageing trains that run in Wales - combine to make the Welsh Government's task heroically ambitious."
In January, MPs on the Welsh Affairs Committee reported that people were tired of "old and cramped" trains provided by Arriva Trains Wales.
The MPs said many problems were due to "a huge failure" to allow for higher passenger growth when the current 15-year franchise was awarded by the now defunct Strategic Rail Authority in 2003.
A Welsh Government spokesman said: "We welcome this very thorough report, which shares our vision for an improved, high quality, integrated transport network in Wales, one which has the passenger at its heart and delivers a service fit for modern Wales.
"We will be considering the detail in this report alongside findings from our own consultation outlining what passengers expect of the new service and look forward to seeing the next rail franchise lay the foundation for a transformed integrated transport network across Wales."


Plans for a giant steam artwork on the Liverpool skyline have been abandoned after 15 months of failed attempts to make it materialise.

Artist Anthony McCall designed Column, a spiral of steam that should have risen 10km (six miles) into the sky.
Arts Council England has spent £535,000 of Lottery money on the project, which was due to have run throughout 2012 as part of the Cultural Olympiad.
The Arts Council rejected accusations that it was a waste of money.
McCall said: "It is with profound disappointment that we have decided to draw our project to a close.
"My team has worked long and hard but, due to the many regulatory and technical challenges, we have not been able to bring Column to completion."
Column was originally due to launch on 31 December 2011 and run for exactly 12 months.
The steam spiral should have risen from East Float dock in Birkenhead and been visible for at least 100km (62 miles) on a clear day, becoming a "nationally and internationally recognised landmark", according to the organisers' original proposals.
But it was repeatedly delayed. The Civil Aviation Authority was worried that it would interfere with aircraft and the Port Health Authority had concerns that it could cause Legionella.
Even after those fears were allayed, the steam-generating mechanism did not work properly and the column still did not appear.
Such vertical steam spirals occur occasionally in nature, when they are known as waterspouts, but nobody has managed to recreate one on this scale by man-made means.
The budget for McCall's project was originally £500,000, including a £40,000 fee for the artist. The budget subsequently rose by £35,410. None of the money will be recouped.
Councillor Jim Crabtree, who represents Bidston and St James on Wirral Borough Council, said it was "a complete and utter waste of public money".
"They should have done their homework before committing £500,000, especially given what we've got going on today - people starving, we've got food banks all over the place. How many people could you feed with £500,000?"
Arts Council England executive director Laura Dyer said she was "disappointed" that the artwork had not been completed but that there was always a risk in commissioning groundbreaking artworks and that in a "very small number of cases" the risk would not come off.
"What became clear, in discussion with the artist and his project team, was that it just couldn't be done within the budget or the timescale on this site," she told BBC News. "I think there comes a point where you have to say we really tried, we worked hard to realise it, but it can't be done."
The Arts Council supervised the project adequately, she said. "We have had milestones along the way where we've managed and monitored the project.
"It is a project that was visionary and testing new approaches and new technical equipment. We did monitor that appropriately along the way but in the end it wasn't able to deliver the vision of the artist."
The project was originally announced in 2009, when the Arts Councils across the UK commissioned 12 artworks to coincide with the London 2012 Olympics.
McCall's plan was chosen from 172 entries for the Artists Taking the Lead project in the north-west. Elsewhere in the UK, the other 11 Artists Taking the Lead commissions - ranging from a set of three crocheted lions in the East Midlands to a new football pitch created in a forest in the Scottish Borders - have all appeared.
Ms Dyer added that every other Cultural Olympiad event went ahead as planned and that most of the money spent on Column had gone into the local economy. "So the investment has been into the region," she said.
"The final project, in all its magnificence, hasn't been realised, but it absolutely is not a waste of money."
The British-born, New York-based Anthony McCall is an internationally renowned artist who is known for using mist, light and projection to create ethereal "sculptures" in mid-air.


Alexander Lukashenko, often referred to as Europe's last dictator, won a fifth term as president in October 2015, with no significant opposition candidate allowed to stand.
President Alexander Lukashenko is entering his fifth term in office
Profile: Alexander Lukashenko
His win in December 2010 was followed by violent confrontations in the capital Minsk between the security forces and thousands of opposition demonstrators protesting about alleged vote-rigging.
A former state farm director, Mr Lukashenko was first elected president in 1994, following his energetic performance as chairman of the parliamentary anti-corruption committee.
A 1996 referendum gave the president greatly increased powers at the expense of parliament and extended his term by two years. He won a further five years in office in 2001 presidential elections condemned as undemocratic by Western observers. Another referendum in October 2004 supported lifting the two-term limit on Mr Lukashenko's rule, allowing him to stand again in 2006 and 2010.
Over the years, several opposition politicians who might have provided leadership have disappeared or been imprisoned. Insulting the president, even in jest, carries a prison sentence.
The president remains defiant in the face of Western pressure for change. He has dismissed all possibility of revolutions such as those which brought an end to old-style regimes in Georgia and neighbouring Ukraine.


Defending champions Middlesex began their County Championship season with a solid batting display at Hampshire.

Sam Robson (84) and Stevie Eskinazi's (82) second-wicket partnership of 105 gave Middlesex a good platform after opener Nick Gubbins fell early on.
But buoyed by their opening-round win over Yorkshire, Hampshire fought back, despite losing both Fidel Edwards and Rilee Rossouw to injuries.
Their bowlers shared the wickets, leaving Middlesex 290-6 at the close.
Middlesex, who were the only side to go unbeaten in the 2016 season, won the toss and elected to bat first at the Ageas Bowl, but suffered an early setback when Gubbins was caught low down by Rossouw at second slip off Edwards' bowling.
After combining for the first wicket, both Edwards and Rossouw left the field - the fast bowler was forced off with a strain after bowling just 5.1 overs, while Rossouw suffered a finger injury attempting a catch.
Robson and Eskinazi took the away side to lunch at 84-1, but were fortunate to stay at the crease much longer as Robson was dropped at second slip on 40, while Eskinazi offered a chance to extra cover on 58.
Former England opener Robson looked fluent as he approached a 18th first-class century, but Gareth Berg had him caught at second slip by Jimmy Adams before Dawid Malan (43) edged Brad Wheal to slip to leave his side 220-3.
Eskinazi was then bowled by Sean Ervine, Adam Voges (24) played onto his stumps from Kyle Abbott and John Simpson sliced to point to expose the lower order at 269-6.
However, captain James Franklin (17 not out) and Toby Roland-Jones (10 not out) reached stumps untroubled to complete a fairly even opening day.
Hampshire director of cricket Giles White told BBC Radio Solent:
"I think we came back well. The lads stuck to their task well and finished the day nicely. But they were a little bit slow up front - a couple of missed chances - but overall I'm relatively pleased with the day.
"Fidel has a hamstring niggle which kept him off the pitch. We'll reassess tomorrow but obviously it's disappointing not to have him out there because he was just hitting his straps and starting to bowl very well when he had to come off.
"We think Rilee has chipped a bone in his finger which is disappointing, but we'll have a look tomorrow and see whether he can bat or not."
Middlesex opener Sam Robson told BBC Radio London:
"On the first day of the year it's always good to get a few runs and settle the nerves and we're in a pretty good position, so it's a good day all round.
"If we can get a few more runs in the morning and then get at them I think there's enough there (for the bowlers)."


Former Wigan Athletic manager Warren Joyce has taken charge of Australian A-League club Melbourne City.

Joyce, 52, has been out of work since being sacked by the Latics on 13 March after four months in charge.
Before joining Wigan, he had spent eight years as Manchester United reserve team manager, and worked with Paul Pogba and Marcus Rashford.
Melbourne City are part of the City Football Group, run by Manchester City's Abu Dhabi-based owners.
Joyce was Hull City's player-manager between 1998 and 2000, then in 2006 joined Royal Antwerp, which at the time was a feeder club for United, and led directly to his move to Old Trafford.
Melbourne City won the Australian Cup last season but a poor A-League play-off campaign ended with elimination by Perth Glory.


A man who was seriously injured in a booby-trap bomb in Crossmaglen, County Armagh, in February has been blinded in one eye as a result of the explosion.

Francis McCabe Jr sustained injuries to his face and chest in the explosion on Corliss Road, close to his home, on 25 February.
At the time, it was reported that he was trying to remove a poster from a lamp post when the bomb detonated.
The poster claimed another person was a security forces informer or "tout".
To date, no-one has been arrested over the explosion.
The following day, police recovered parts of what was believed to have been an exploded pipe bomb from the scene.
On Tuesday, the Irish News reported that although surgeons battled to save his injured eye, Mr McCabe will "lose his sight permanently".


Five men have appeared in court accused of misusing the camera on a police helicopter to film people who were naked or having sex.

Two serving police officers, a retired police officer, a current pilot and a retired pilot were arrested as part of a South Yorkshire Police investigation.
Reports had been made that the force's helicopter had been used for inappropriate filming, Sheffield Magistrates' Court heard.
All five are charged with misconduct.
The charges relate to four alleged incidents between 2007 and 2012.
Mr Lucas and Mr Walls are both currently suspended from duty, South Yorkshire Police confirmed.
District Judge Naomi Redhouse granted the men bail, with the next hearing due at Sheffield Crown Court on 7 June.


A £30,000 award for UK-based sculptors is to be created by the The Hepworth Wakefield gallery as part of its 5th anniversary celebrations.

The prize, to be awarded every other year, will be open to artists who have made "a significant contribution to contemporary sculpture".
The four shortlisted artists for the first award will go on show at the West Yorkshire gallery next October.
The £35m gallery, named after sculptor Barbara Hepworth, opened in May 2011.
It has since had around 1.4 million visitors and generated £20m for the local economy, according to the gallery.
The sculpture award will be open to artists of any age and at any stage in their career who make sculpture "in its broadest definition".
The prize will be funded by benefactors including TV executive and Hepworth Wakefield chairman David Liddiment; art collector David Roberts; Linda Harley, who founded shoe chain LK Bennett; and local company Litestructures.
The gallery's fifth anniversary programme will also include the first UK survey of works by artist Stanley Spencer for 15 years and a retrospective of photographer Martin Parr, including new photographs of Yorkshire's "Rhubarb Triangle".
Works by artists including Henry Moore, Antony Gormley and David Hockney have been donated to the gallery by collector and former BBC journalist Tim Sayer, and will also go on display.


A prosecutor has told jurors there is a "compelling case" against a man accused of murdering a former Mr Scotland bodybuilding champion.

Steven Kirkwood, 44, denies murdering Michael O'Hanlon by repeatedly stabbing him at HK Autotek, Stevenston, Ayrshire, last July.
He has lodged a special defence of self-defence.
In his closing speech, prosecutor Richard Goddard said the "right thing to do" was to convict Mr Kirkwood.
The jury has heard that abusive texts and Facebook messages were being sent by Mr Kirkwood to his ex-partner Eileen O'Hanlon, who was due to marry Mr O'Hanlon in August last year.
A meeting was set up in the garage on 25 July 2016 to talk over the situation.
There was a struggle and Mr O'Hanlon was stabbed four times and died from massive blood loss.
Mr Kirkwood admits stabbing him, but claims he was acting in self-defence. He said he found the knife on the floor and lashed out because he was pinned down by Mr O'Hanlon and his friend Forbes Cowan.
Mr Goddard told the jurors that Mr Kirkwood had spoken about stabbing Mr O'Hanlon and had said "I think I killed him", 45 minutes after the incident in the garage.
"We have evidence of what eye-witnesses saw, evidence of what Steven Kirkwood admitted to others what he had done in the aftermath of the incident," he told jurors.
Mr Kirkwood had also posted on social media that his ex-partner Ms O'Hanlon had called him a nutcase for years and added: "I'm now going to show them nutcase."
Mr Goddard told the jury: "He started the day posting those words and ended it by stabbing Michael O'Hanlon to death."
The prosecutor added: "There is no evidence the knife was ever in anyone else's hands."
Defence QC Derek Ogg, in his closing speech, said that on the day of the incident Mr Kirkwood had found himself facing two big, powerful men - the reigning Mr Scotland bodybuilding champion Mr O'Hanlon, who was 6ft and 17 stone, and 6ft 4in Forbes Cowan, who was a runner-up in the World's Strongest Man competition.
Mr Ogg said: "These are two big, powerful, strong men. You could not get bigger and stronger men in Ayrshire than these two.
"He used what force he thought at the time was necessary to stop these two big powerful men each of whom had expressed aggression towards him.
"My client has severe arthritis. These men were not just looking for violence, but serious violence. Mr Kirkwood could only escape by going through these two men."
He added: "There was no conversation about resolving any issue. They intended to do violence and wicked violence to my client.
"These are men of such height and strength that if these two came through a door aggressively anyone would be thinking: 'This is it. I'm in for it.'"
"If you had an elephant lying there and you saw these two men coming you would go for it."
The defence QC accused Crown witnesses of being selective with their evidence.
The trial before judge Lady Rae continues.


Pressure will not force Arsenal manager Arsene Wenger to resign, says former Gunners defender Lauren.

Wenger's side face Southampton in the Premier League on Wednesday and a win would lift them into fifth.
The Frenchman, whose contract expires at the end of this season, has been criticised by some fans this term.
Lauren, 40, told BBC Africa: "He knows how to deal with pressure, hopefully things will be in the right way sooner or later."
Lauren played 159 league games for Arsenal between 2000 and 2007 and was part of the "invincibles" side that won the 2003-2004 league title.
The former Cameroon right-back said: "I don't think he will resign. He's been under pressure for 30-35 years, managing big clubs with big pressure."
In February Wenger said he would decide on a new contract in March or April, but later said that he made a mistake in giving that timeframe.


US citizens should be refused visa-free access to the EU in response to American visa rules affecting citizens from five EU countries, the European Parliament has said.

Citizens of Bulgaria, Croatia, Cyprus, Poland and Romania are currently denied visa-free access to the US.
The European Parliament passed a non-binding resolution on Thursday.
However, member states would have to approve the move, a process that could take years.
Nevertheless, the resolution, passed by a show of hands, said the new visa rules should come into effect quickly and should remain in place until the US visa requirements were shelved.
A European Parliament statement said the EU Commission was legally obliged to temporarily reintroduce the new visa rules because of its reciprocity policy.
The end of American exceptionalism?
US tourism industry fears downturn
Trump travel ban: Pre-clearance and why it matters
Under these rules, "if a third country does not lift its visa requirements within 24 months of being notified of non-reciprocity, the EU Commission must adopt a delegated act... suspending the visa waiver for its nationals for 12 months", the statement said.
It said a notification of non-reciprocity was first received in April 2014 - meaning the Commission should have taken action in April 2016 - but so far it has yet to do so.
Canada also has visa requirements for Bulgarian and Romanian citizens, the statement said, but it has announced that these will be shelved in December.
In January, President Donald Trump attempted to introduce a travel ban on people from seven mainly Muslim nations but it was blocked in the courts. He is working on a new executive order.


British Cycling has revealed that David Millar, the former British road race champion who served a two-year doping ban, is mentoring its academy riders.

Miller served his ban from 2004 to 2006 after admitting using blood-boosting agent EPO early in his career.
The 39-year-old returned to the sport and has volunteered to educate Britain's young riders.
Technical director Shane Sutton said "nurturing an anti-doping culture" was at the heart of British Cycling.
Millar won stages in road cycling's three most prestigious stage races - the Tour de France, Vuelta a Espana and Giro d'Italia - and also won 2010 Commonwealth gold for Scotland in the road race time trial.
The Scot, who retired in 2014, is regarded as one of the sport's leading anti-doping campaigners.
Sutton added: "Having someone of David's calibre on board to support us in this education process is invaluable. He is readily available to share his well-rounded experiences as a professional cyclist to the young riders who aspire to succeed in their careers.
"David will work with the squad on a voluntary basis until the end of the month with a view to subsequently joining the team in a more official capacity."


Former Scottish health minister Susan Deacon is set to become the first woman to chair the Institute of Directors in Scotland.

Ms Deacon will succeed Ian McKay when he stands down as chairman at the IoD Scotland conference on Friday.
She was elected as Labour MSP for Edinburgh East and Musselburgh in 1999 and served as Scotland's first health minister following devolution.
Ms Deacon stood down from elected office in 2007.
She has since worked across the private, public and third sectors and is currently a professorial fellow at the University of Edinburgh.
Ms Deacon is also a non-executive director of Scottish Power Ltd, Lothian Buses Ltd and the Institute of Occupational Medicine.
Mr McKay said: "The future of the IoD is in excellent hands with Susan at the helm.
"Her varied experience and approach to leadership will be of real benefit to the IoD at a time when boards are increasingly embracing change."
Commenting on her appointment, Ms Deacon signalled her intention to build on IoD Scotland's work on promoting strong leadership and governance.
She said: "Successful organisations need effective leaders - it's that simple.
"If Scotland is to continue to grow and flourish on a world stage we need to support the leaders of today and to grow the leaders of tomorrow.
"So too must our boardrooms have within them a diverse range of skills and experience and operate to the highest possible standards.
"I am very proud to be taking on the role of chair of IoD Scotland, an organisation which has been at the forefront of promoting high standards of leadership and governance."


Premiership side Sale Sharks have announced the cross-code signing of Castleford Tigers winger Denny Solomona on a three-year deal.

The 23-year-old was registered in Sale's Champions Cup squad last week despite the move not being confirmed.
Cas are taking legal action after Solomona did not report for pre-season having "resigned" from rugby league with two years left on his contract.
"He is a great player," said Sale director of rugby Steve Diamond.
"He has an eye for scoring tries and has the added bonus of having played rugby union in his time at school and college."
Solomona broke Lesley Vainikolo's record for the most tries in a Super League season this year when he crossed 40 times.
He has joined fellow winger Josh Charnley in making the switch to the 15-a-side game with Sharks.
Despite the deal being done, BBC Sport understands that Sale could end up paying Castleford a compensation fee for signing Solomona.
The Tigers are prepared to take the issue to the High Court and have appointed London barrister Nick Randall QC and Leeds-based sports lawyer Richard Cramer to fight their case.
Rugby Football League chief executive Nigel Wood spoke about his concerns about the "implications for the game" because of Solomona's breach of contract.
The RFL have discussed the transfer with the Rugby Football Union and Premiership Rugby.
New Zealand-born Solomona, who made his Samoa debut in a rugby league international against Fiji in October, was contracted to Castleford until 2018.


Internet giant Yahoo continues to struggle, reporting declining ad revenue in the second quarter of 2013.

The results were the first since the company acquired blogging platform Tumblr for $1.1bn (Â£723m) in June.
Profits were $331m, up 46% from the same time last year. The rise was due mostly to the company's investment in Chinese ecommerce site Alibaba.
Display advertising revenue fell 13% in the quarter, while search revenue was down 9%.
Chief executive Marissa Mayer, who celebrated one year at the company on Tuesday, chose to ignore the continued revenue slide. Instead, she hailed the company's relentless release of new mobile offerings.
"We reached a pace of launching a new product almost every week," said Ms Mayer during a webcast to discuss the company's earnings.
"As you can tell, we've been busy."
Reaction on Wall Street was muted, with shares falling 1.7% on the news.
Although the company's stock has risen more than 70% since Ms Mayer took over, fundamental issues of revenue generation remain.
While digital ad sales are expected to grow overall this year, it is unclear whether Yahoo will be able to get in on the game.
According to research firm eMarketer, Yahoo's share of global digital ad spending is expected to decline to 3.1% in 2013 from 3.37% last year.
In the US, eMarketer estimates that Yahoo's share of US digital ad revenues will decline to 8% from 8.6% in 2012.
But Yahoo's turnaround is expected to take longer than one year and Yahoo's board is said to have promised Ms Mayer several years to help revamp the company's fortunes.
She herself has said that her focus at the company would be on its mobile offerings. The earnings release proclaimed the many mobile revamps to its products, such as photo-sharing site Flickr and Yahoo News, conducted under her tenure.
Yahoo has also bought nine technology start-ups in the past quarter, including Tumblr and Summly, bringing the total to 17 acquisitions under her watch.
Yahoo hopes this will diversify its base, attract engineering talent and boost company morale.
Ms Mayer touted the improved environment at the company, noting that in the second quarter, the rate of employees leaving the company declined by 59%.
She also noted that more than 12% of new hires in the past year were boomerangs - that is, people who left Yahoo only to come back.


A South African judge has ruled that prosecutors can appeal against the acquittal on murder charges of Paralympic athlete Oscar Pistorius.

The double amputee was jailed for five years in October for killing his girlfriend, Reeva Steenkamp.
Judge Thokozile Masipa said prosecutors could appeal against the acquittal, but not the five-year sentence given for the lesser charge of culpable homicide.
Pistorius' lawyers had opposed the appeal request.
The case will now go before South Africa's Supreme Court of Appeal.
Why Pistorius and Dewani cases are not failures
The athlete's father Henke Pistorius said it "should not have gone this far", AFP news agency reports.
"Oscar is strong, he has to be strong, he grew up like that. There's lots of things in life, especially for a man like him  that is... not fair," he is quoted as saying.
Prosecutors argued that Judge Masipa misinterpreted the law when she cleared Pistorius of murder on the basis that he did not intentionally shoot Ms Steenkamp.  Judge Masipa granted the appeal in the ruling in a Pretoria court on Wednesday.
"I cannot say... that the prospect of success at the Supreme Court of Appeal is remote," she said.
However, Judge Masipa dismissed the prosecution's argument that the sentence should be reviewed because Ms Steenkamp's parents had been extremely dissatisfied with it.
She also said the public interest in the case was "irrelevant" and she had ruled only on the basis of the prosecutors' case.
In court - By Pumza Fihlani, BBC News, Pretoria
Today was a big win for the state prosecutors. Although they lost their bid on the sentence, Judge Thokozile Masipa gave the go-ahead for them to appeal the conviction. This was always Gerrie Nel's main intention.
The Supreme Court of Appeal (SCA) will now decide if the principles of law were applied correctly.
A panel of up to five judges has the power to not only overturn Judge Masipa's conviction but can also rule on a minimum sentence - which in the case of murder would be 15 years in prison.
Although the sentence appeal was denied, veteran advocate Mannie Witz told me that before the SCA this would make little difference. The appeal judges' power is such that they can also consider the sentence and find that the appeal should have been granted.
For Pistorius, this means the case is far from over and if the state has its way, the worst is yet to come.
Outlining his case on Tuesday, prosecutor Gerrie Nel said the sentence was "shockingly inappropriate and does not fit the crime and the accused".
Pistorius could be eligible for parole and house arrest after serving 10 months of his five-year sentence.
He will remain in prison while the appeal process takes place.
Prosecution spokesman Nathi Mncube welcome the judge's ruling on Wednesday but said prosecutors would still attempt to challenge the sentence.
The prosecution had called for the maximum 15-year sentence for culpable homicide, or manslaughter.
Ms Steenkamp, a model and law graduate, was shot dead at Pistorius' home in Pretoria in the early hours of Valentine's Day last year. He said he feared there was an intruder.
Pistorius was acquitted by Judge Masipa of both premeditated murder and the lesser murder charge of dolus eventualis, also known as common-law murder.
In South African law, this charge applies if the accused knew they might kill someone but still went ahead with their course of action.
Pistorius is serving the sentence in the hospital wing of Pretoria's Kgosi Mampuru II prison.
The appeal is likely to be heard next year.


Pope Francis has celebrated Mass at St Peter's Basilica in the Vatican, at the start of a synod of Roman Catholic bishops focusing on family issues.

The run-up was dominated by a row over a Vatican priest who on Saturday announced he was in a gay relationship.
Poland-born Krzysztof Charamsa said he wanted to challenge the Church's "backward" attitude to homosexuality.
He was later dismissed from his post at the Vatican's office in charge of guarding Roman Catholic doctrine.
A Vatican spokesman said Monsignor Charamsa's decision to give interviews on the eve of the synod was "grave and irresponsible" and would put Pope Francis under "undue media pressure".
In an interview with the Corriere Della Sera newspaper, the 43-year-old priest said: "It's time the Church opened its eyes and realised that offering gay believers total abstinence from a life of love is inhuman."
The controversy has set the scene for what some fear could be a fractious three weeks, says BBC religious affairs correspondent Caroline Wyatt.
The Synod - a defining moment for Pope Francis
Almost 300 Church leaders - and some lay people - will be discussing such issues as the treatment of Catholics who are gay, and how to approach couples who live together without being married or wish to take communion after being divorced.
Analysis: Caroline Wyatt, BBC News
It is the most highly-anticipated meeting of the leaders of the Roman Catholic church since the Second Vatican council, some 50 years ago.
In his homily today, the Pope spoke of the importance of the family - and perhaps rather pointedly, of the love between a man and a woman. He also said that the wealth of the developed world hadn't led to greater happiness, but to loneliness, and higher rates of abortion and divorce.
Many campaigners and more liberal Catholics would like to see a change in Catholic doctrine on issues ranging from homosexuality to contraception.
But while some bishops here do want reform, others remain fiercely opposed. In the end, though, the synod is not a democracy. It will be up to the Pope to decide what - if anything - changes, and how the Church applies its teaching to its sometimes errant flock.
The Pope has called for a more understanding attitude on sexual issues.
After his election in 2013, Pope Francis reaffirmed the Roman Catholic Church's position that homosexual acts were sinful, but said homosexual orientation was not.
"If a person is gay and seeks God and has good will, who am I to judge?" he said.
The issue of homosexuality was also highlighted during the Pope's visit to the US last week.
He had a private meeting with a gay former student of his and his boyfriend at the Vatican mission in Washington.
The Pope also met Kim Davis, a Kentucky local official who recently gained attention for refusing to issue marriage licences to same-sex couples.


Bayern Munich have confirmed assistant manager Paul Clement has been given permission to speak to Swansea City.

The Swans are bottom of the Premier League and are set to appoint the former Derby County boss on Tuesday.
Clement had been interviewed by Swansea prior to former manager Bob Bradley's appointment in October.
The 44-year-old is set to be their third boss of the season and is likely to be at Selhurst Park on Tuesday for Swansea's game against Crystal Palace.
More to follow.


A 37-year-old man has died after being struck by a car on the M8 between Livingston and Bathgate.

Emergency services were called to the accident at about 20:30 on Friday.
It happened on the westbound carriageway between junction 3 Livingston and junction 3A Bathgate.
The road was closed for about six hours. Police have appealed for witnesses.


A project in County Fermanagh that helps older people research their family history has brought in technology experts from very close to home.

Frank McHugh runs the genealogy workshops in Lisnaskea.
Mr McHugh was finding that technology was becoming a barrier for some of the older people he works with.
He decided to ask the grandchildren of the participants for help.
"There's so much in the way of resources on the internet and really the young people were there to help the older people access the technology much, much quicker," he said.
"I could spend more time working on the genealogy side of things in terms of uncovering the different stories," he added.
Adam Porter helped his great granny Eileen Stott get to grips with technology and Eileen admits she's "not up to speed at all".
Adam said: "She doesn't really know that much about technology, but I've definitely helped her and I've enjoyed it."
Adam was also interested in learning about his family tree.
"I have always wanted to know who I really came from and who was in my family, who my ancestors were and I've definitely found some of it out."
The research was organised by Fermanagh and Armagh Connected Together (FACT) which helps to tackle rural isolation through intergenerational schemes such as this.
Project Worker Sharon Howe said it had been a success:
"We knew we had an interest from the older people because we've run genealogy classes regularly but we really weren't sure how the younger people would engage and to be honest we have been absolutely delighted."
She said: "Some of the younger people have been so enthusiastic, they've gone out of their way to contact relatives.
"It's brought relatives back together again."
Frank McHugh believes that while technology can be a problem for the older generation, it can also prevent young people from learning about their past:
"The opportunity for a grandchild to sit down and talk to their grandparents about the grandparent's life, about stories within the family, it's very, very rare. I suppose kids are so focussed sometimes on the Xbox or other types of new technologies that those old fashioned types of conversations just don't happen.
"Hopefully what will happen is the young people will be left with an experience that will be there for the rest of their lives and they will have gained information and I know looking at some of the young people they were so enthused by the conversations that they had."
The six families involved in the project were supposed to research as far back as their great grandparents.
Eleven-year-old Dylan Howe became so obsessed that he admits: "I've found more than I should have found, very far out cousins that I couldn't really figure out how they were related to me."
His family tree now covers a roll of paper several feet long.
Talking to his relatives also uncovered a story that had been forgotten.
"My great-great grandmother's brother, William Kelly was on the Titanic as an apprentice electrician and went down with it at 23 years of age."
Dylan spoke to a great-great aunt who eventually told him of his family's connection to the tragedy.
"My nanny didn't even know that, and my father or even anyone else in the family didn't know that."
He had studied the Titanic at school and said his teacher Mr Wilson would "probably be very proud that I found that out."
Frank McHugh is also glad that the story has been uncovered.
"That story was completely lost to the family so the process of working on the genealogy, being able to look at all of the resources out there, one conversation led to another little bit of information and the story has unfolded and that story will be there with the family for the next generation," he said.


South African teams Cheetahs and Southern Kings are set to join the Pro12 as early as September 2017.

The two sides are expected to be cut by South African rugby union authorities from Super Rugby on Friday, 7 July as the southern hemisphere competition is reduced from 18 to 15 teams.
That will pave the way for them to join teams from Wales, Ireland, Scotland and Italy in a 14-team league.
The new format is set to start for the 2017-18 season.
Celtic Rugby Limited - which governs the Pro12 - Cheetahs, Southern Kings and the South African Rugby Union have all been contacted by BBC Wales Sport but declined to comment.
Teams will play on a home and away basis but what has yet to be agreed is the format of the competition, whether it will be played as one 14-team league or more likely two conferences of seven.
There has been speculation the South African sides could play some of their home matches in the United Kingdom, with Saracens' Allianz Arena mooted as a potential venue.
This would be the first major change to the Pro Rugby competition since the introduction of Italian sides in 2010.
Welsh and Scottish sides first combined in a league in 1999, before an agreement with the Irish Rugby Football Union saw the Celtic League formed in 2001 with 15 teams.
Now the tournament is set for another shake-up with the introduction of Cheetahs, based in Bloemfontein, and Port Elizabeth-based Kings.
The Cheetahs had already been approached to join the league.
Both are widely expected to lose their Super Rugby status amid a downsizing of the competition from 18 teams to 15.
The South African Rugby Union and Sanzaar have indicated the decision will be made and announced on 7 July.
South African authorities have called a special meeting for that day to decide which two of its six teams will be dropped from Super Rugby.
As well as the two discarded South African sides, Australia will also lose one of its five representatives in the competition which also includes teams from New Zealand, Argentina and Japan.
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SARU is eager to align with a northern hemisphere tournament, which has a similar time zone, to make cross-border games compatible for television broadcasters.
This latest development could also open the door to North American participation for the following 2018-19 season, as the Pro12 explores options for expansion to generate more revenue and tap into new markets.
Welsh Rugby Union chairman Gareth Davies insisted nothing had been finalised but welcomed the future prospect of South African sides joining the Pro12 competition.
"I can't tell you probably any more than has already been stated," Davies told BBC Wales Sport.
"There are discussions going on, which people are aware of, between the Pro12 and South African rugby union and the franchises down there.
"There is a desire from the South African teams I think to join the Pro12 and I think the Pro12 would like them to join.
"The Pro12 itself is a cross border competition already and this just extends this.
"It makes for a promising and exciting future, if it did happen.
"At the moment it looks like the two teams from Super Rugby that will not be in the competition next year will join (the Pro12).
"I suspect there will be interest further afield from South African teams as well.
"It just expands the tournament and I think it's an opportunity to develop the game within the northern hemisphere.
"There is still a lot of work to be done in terms of the legal complexities with issues such as broadcasting, commercial and most important, player welfare with all the travelling that has to be done and the logistics associated with that."


The Scottish government should "get to grips" with a "calamitous" attempt to reform agricultural payments, a farmers' union has said.

NFU Scotland said a "damning report" from the auditor general into the programme showed it may never be fit for purpose.
Audit Scotland has highlighted "serious cost and operational issues".
The Scottish government said it was focused on paying crofters and farmers before the 30 June deadline.
If the system does not meet European Commission regulations by that date, the Scottish government could face a penalty of between  £40m and £125m.
Under the Common Agricultural Policy (CAP), about £4.6bn in European and Scottish government funding will be paid out between 2015 and 2020.
The money is mainly given to improve agricultural productivity and to ensure farmers have a reliable income.
The CAP Futures programme in Scotland was meant to make the rural payment process more efficient.
However, in their fourth update on the scheme, auditors said the programme had "serious cost and operational issues", particularly with the slow delivery and poor performance of the new IT system that processes support claims.
Audit Scotland said this had caused lengthy delays which have had a negative impact on farmers - many of whom were already experiencing financial difficulties caused by low milk prices and severe flooding.
NFU Scotland President Allan Bowie said the report showed how poorly Scottish farmers and crofters had been served.
"Far from being 'back on track', the legacy of failure is continuing and this report will guarantee that confidence in the system remains shot," he said.
"The first job of our new cabinet secretary must be to get to grips with this debacle and ensure that the system becomes compliant and is fully functional before the money runs out."
Fergus Ewing was appointed as the new rural economy secretary in a cabinet reshuffle on Wednesday.
Caroline Gardner, Auditor General for Scotland, said the project had faced "serious challenges since the beginning" and had suffered "a number of failures" in the way it had been been managed.
She told BBC Scotland: "We found delays in getting the system up and running and the speed at which it does its work means that farmers don't know what their final claim will be.
"Around 80% of them have now received an initial payment but 20% haven't received anything yet - and we are heading towards the European Commission's deadline of 30 June for making final payments."
Ms Gardner's report also highlights a conflict of interest within the leadership team of the programme, revealed by a BBC investigation in March.
BBC Scotland found that a former delivery director of the project, Dominic Prabhu, had supplied dozens of contractors from his own company to work on the programme.
His company Spectromax Solutions saw its assets soar last year - from about £81,000 in 2014 to about £3.5m in 2015.
Dr Prabhu has denied there was a conflict of interest.
Auditors said the Scottish government was aware of a conflict after being notified by a whistleblower and said "there was an opportunity for the delivery director to benefit financially from the programme recruiting from his company".
The report added: "The Scottish government set up a resources group in March 2015 to ensure that recruitment decisions were not taken by an individual.
"The delivery director was a member of this group, and therefore still had the opportunity to influence recruitment decisions... The delivery director was still able to sign off overtime claims for contractors, including those coming through his agency.
"The delivery director should not have been on the resources group and allowed a direct involvement in recruitment decisions."
The cost of the programme was originally estimated to cost £102m, but it now has a final budget of £178m and a reduced scope.
Scottish Labour demanded that the SNP make an "urgent statement" to parliament about the "catastrophic IT failure", while the Conservatives said the government had "taken their eye off the ball" and failed rural communities.
The Scottish Greens said the IT shambles was "inexcusable" given the importance of the industry to Scotland.
Deputy First Minister John Swinney told BBC Scotland: "I am a member of parliament that represents rural Scotland. I know the difficulty and the challenges that this has presented for the farming industry."
Mr Swinney said the new rural economy secretary, Fergus Ewing, would make a statement to parliament once he had studied the detail of the report.
He said: "We are one of the first countries in the EU to pay farming support.
"I appreciate there has been slippage of about four months for many of the payments that have been made to farmers, but by the intervention of the first minister and by the working of this system, we have made sure that a comprehensive range of payments have been made to farmers as part of the commitments that we gave."


Dolly Parton has become the latest celebrity to use the phrase "ay up me duck".

The country singer gave the East Midlands greeting in a video address to launch her Dolly Parton Imagination Library in Nottingham.
The scheme sends free books to children from birth until their fifth birthday.
Parton followed Angelina Jolie, who baffled audience members in Hollywood when she said "ay up me duck" to Derby actor Jack O'Connell.
Her book scheme is already running in Bilborough, Hyson Green, Radford, Dunkirk and Lenton for several years.
The city council hopes the scheme, which is being extended to Aspley, Arboretum, Bulwell and St Ann's, will improve child literacy rates.
In Nottingham, only 60% of four-year-olds meet expected reading standards - compared to the national average of 74%, the authority said.
The initiative is being rolled out as part of the Â£45m Small Steps Big Changes project, which the council said was set up to give those aged three and under "a better start in life".
Councillor David Mellen said: "Through working together with Dolly's charity we can encourage more parents to explore books at home with their children.
"We know this will help them to start school with a much greater confidence."
Dolly Parton said: "This program is one of the most important ways I know to improve the educational opportunities for children in our communities.
"I am most proud of the fact that every child in the Imagination Library does not have to grow up without books in their home."


A senior Labour MP has called on Theresa May to step aside and "let us have a go" at forming a government.

Llanelli MP Nia Griffith - the shadow defence secretary - said Labour had to be ready "at any moment" to take over.
The Democratic Unionists have agreed in principle a "confidence and supply" deal with the Tories, who lost their majority in Thursday's election.
Wales Office Minister Guto Bebb said "the only option" was a Tory government with support from other parties.
Downing Street said the details of the outline deal would be discussed at a cabinet meeting on Monday.
Labour has suggested it could form a minority administration, but with 262 seats falls far short of the 326 needed for a majority in the House of Commons.
Leader Jeremy Corbyn has ruled out striking a deal with other parties.
Ms Griffith told BBC Radio Wales: "What we really want to be about is making sure we can try, if we can, to put some of our ideas into practice, and that means being a very united group in parliament.
"It means being ready, at any moment, to take over and step into government whenever there might be a chance.
"We're still saying quite clearly that we would be ready to take over if Theresa May cannot cobble something together, and we're very doubtful that she can.
"We don't really think she has a mandate to now, she's really made a fool of herself and really, quite frankly, she should step aside and let us have a go."
Mr Corbyn had given his party "confidence" about selling party policies such as public ownership of the railways, she said.
On Thursday, Labour won back three seats from the Conservatives in Wales - Cardiff North, Gower and Vale of Clwyd.
Ms Griffith said voters had switched to Labour during the election campaign itself.
"People have a real sense of community in Wales," she said.
"They like Labour ideas like looking after public services and I think people came together, they saw what Theresa May was offering, which was very empty - I can't really call it a manifesto - and they saw her arrogance and almost disdain for people, and they really did not like that.
"What was interesting was the number of people who made up their minds during the campaign; we saw things swinging at the very last minute."
Last June, Ms Griffith joined a Labour rebellion against Mr Corbyn following the referendum vote for Brexit, resigning as shadow Welsh secretary in protest at what party critics claimed was his half-hearted campaign in favour of remaining in the European Union.
She returned to the front bench in October as shadow defence secretary after Mr Corbyn defeated a challenge to his leadership from Pontypridd MP Owen Smith.
Mr Bebb dismissed the idea that Labour could take power.
"It's very clear to me that the only option on the table, to be perfectly frank, is a Conservative government supported by some other parties in Westminster," he said.
"The DUP have voted on a fairly regular basis with the Conservative Party in the past so the nature of any agreement is something for the prime minister to work out.
"But it's not surprising that there is a possibility of a Conservative minority government being formed with the support of the DUP.  I don't find that in any way surprising."


A multi-million pound redevelopment project in Aberystwyth could move a step closer this week.

Plans have been put forward to transform Aberystwyth University's Old College into community facilities, including exhibition space, artists' studios and a cafe/restaurant.
The project also includes developing its Assembly Rooms and other university buildings in the area.
A public consultation event will be held at the Old College on Tuesday.
Speaking ahead of the consultation, the university's Pro Vice-Chancellor Dr Rhodri Llwyd Morgan said the vision was to develop the Old College into "a dynamic hub of learning, heritage and culture".


The last avalanche forecast of the latest Sportscotland Avalanche Information Service (SAIS) season has been published.

From December to the middle of April, the organisation assesses the risk of snow slides in five areas - Creag Meagaidh, Glencoe, Lochaber, Northern Cairngorms and Southern Cairngorms.
This winter, Torridon was added on a trial basis.
The latest season recorded one of the highest numbers of avalanches in years. Following a record high last winter, there were no deaths caused by avalanches this time around.
A warning to off piste skiers and snowboarders in the Southern Cairngorms.
Initial figures suggest 350 avalanches were recorded by the SAIS. Service co-ordinator Mark Diggins said: "We have had more reported naturally-occurring avalanches this year than last, although this number is a guide only as many more avalanches may have taken place but not been recorded."
The higher rate of avalanches was largely due to continual stormy weather periods with significant snowfall above 600m (1,968ft) interspersed with sharp temperature rises, said Mr Diggins. He added: "Because of the significant amount of snow accumulation a number of these avalanches were very large and travelled long distances."
The stormy weather - particular frequent high winds that can be seen above blowing streams of water uphill in Lochaber - impacted on the numbers of people visiting Scotland's mountains this winter. Mr Diggins said: "It has been a frustrating winter for climbers, walkers, skiers and boarders, but many mountain goers have been aware of the heightened hazards this winter and have been more selective in what they do and where they go."
The latest SAIS season saw no avalanche-related fatalities, whereas avalanches caused the deaths of eight people during the 2012-13 season - the highest figure in years.
One of the greatest avalanche risks this winter was large overhanging edges of snow, called cornices.
A crack in a large cornice documented by the SAIS Lochaber forecasting team. The overhangs are created by heavy snowfalls and persistent winds blowing in generally the same direction. Mr Diggins said: "In the Lochaber area, senior forecaster Graham Moss identified that we had twice as much snowfall than last winter."
A lump of fallen cornice in Lochaber.
Several of the forecasters were accompanied by their dogs on avalanche risk assessments. The dogs also helped to illustrate the wintry conditions in images uploaded to the SAIS blogs.
An "avalanche hound" at Lochnagar in the Southern Cairngorms.
"The winter has been a challenging one for the SAIS forecaster team," said Mr Diggins. "Not only because of the strong winds and blizzards presenting physical challenges, but also the very dynamic weather systems presenting a continually changing snowpack situation which required considerable focus in producing the daily avalanche forecasts."


Birmingham City have signed defender Marc Roberts from Championship rivals Barnsley for an undisclosed fee.

The 26-year-old, who joined the Tykes from National League side Halifax in 2015, has agreed a five-year contract with Harry Redknapp's Blues.
Barnsley captain Roberts played 40 times in 2016-17 as they finished 14th in their first season back in the second tier after promotion.
"I'm happy to be at such a big club," Roberts told Birmingham's website.
"There's been a lot of rumours and a lot of clubs interested but when a manager like Harry Redknapp comes along and asks for your signature you've got to take it seriously."
Find all the latest football transfers on our dedicated page.


A 21-year-old man has been killed in a crash on the outskirts of Ballymena, County Antrim.

The crash, involving a car and a coach, happened on the Moorfields Road at about 13:00 BST on Sunday. The road remains closed.
The name of the man who died has not yet been released.
Police have appealed for anyone who witnessed the crash to get in contact with them.


Nearly 50 people have been arrested at protests in Ferguson, Missouri, over the shooting of an unarmed black teenager two months ago.

Civil rights activist Cornel West was among those held after he led a march to the police station.
Riot police lined up outside the building and arrests were made when people tried to break the line.
The protests were part of four days of events called "Ferguson October", which calls for an end to police brutality.
Demonstrators also demanded that charges be brought against the white officer who killed Michael Brown, 18, at the start of August.
The shooting sparked weeks of unrest and made national and international headlines.
A grand jury is deciding whether to bring charges against the officer.
The protest began on Monday morning when demonstrators marched with arms joined from Wellspring Church to the police station in heavy rain.
The names of people killed by police across the US were read out, and those included Venderrit Myers Jr, another 18-year-old killed last week by a white police officer in nearby St Louis.
Police say Myers, who was black, shot first but they are investigating why 17 shots were fired by the officer.
Outside the police station, the chalk outline of a man was drawn on the ground, which organisers said was "a memorial for the body of Michael Brown".
Bishop Wayne Smith of the Episcopal Diocese of Missouri told US media his faith compelled him to be there.
"I want to show solidarity, and call attention to the structural racism of St. Louis," he added.
Ferguson Police said 42 people were arrested at the police station and another six were arrested for blocking a street elsewhere.
On Monday night, the protests focused on two Walmarts and a political fundraising event.


An intrigued Rory McIlroy peered into the bag of a potential rival for the Abu Dhabi title last week and marvelled at the unique set of clubs.

The four times major champion wasn't alone - other big names, including Ernie Els, peppered the clubs' owner with questions. Never mind that Bryson DeChambeau is more than half Els' age, the big South African wanted to learn from the young amateur.
In a golfing world of uniformity and convention, DeChambeau brings an approach to the swing and equipment that is unique in the modern game.
Furthermore, it seems to work. The 22-year-old is the reigning US amateur champion, becoming only the fifth man to land that prestigious title and the National Collegiate Athletic Association (NCAA) individual crown in the same year.
Competing against pros, he was runner-up to Peter Senior at last year's Australian Masters. Last week DeChambeau was the first-round leader after an opening 64 in Abu Dhabi, where he eventually finished in a share of 54th place.
The Californian says he is doing a form of internship before turning pro once he has competed at the Masters in April. He will be one of the most talked-about players in the Augusta field.
DeChambeau calls himself "a golfing scientist". He is a physics major and has evolved a game that hinges around those unique irons that so fascinated McIlroy when they played together in the third round last week.
Throughout the bag, each iron is 37 and a half inches long, whether it is a three-iron or a wedge. He wields them with the same upright swing, wrapping his palms around chunky grips rather than using his fingers to hold the club.
"They're all the same length," DeChambeau told BBC Sport. "Same lie angle, same shaft, just different loft. Same bounce configuration as well on each and every one of them.
"But it's four degrees of loft difference between them and it works pretty well. It helps me keep my same posture, same set-up, same everything, and allows me to perform quite nicely with my irons."
The idea came from a book called 'The Golfing Machine', self-published by Homer Kelly, a Seattle aircraft mechanic, in 1969.
Californian golf instructor Mike Schy came across the book and was intrigued by Kelly's theory surrounding "geometric oriental linear force" and the impact it could have on a golf ball.
It also appealed to the scientist in DeChambeau.
"He's steadfast," the player's mother Jan told Golf Digest magazine. "Once something is proved to him, he stands his ground."
That determined streak comes from his father John, who was once one of northern California's top amateur golfers.
The younger DeChambeau collaborated with his coach to refine the Golfing Machine to suit his game.
"We thought there has to be a better way to play golf," he told me.
"It's a long story, but to keep it short I pretty much chose this variation of the golfing machine where it allowed me to swing on the same plane.
"And when I did that, I realised I couldn't do it with a wedge and a three iron because it would mean changing body motions. That doesn't make sense, so I said why don't we make them all the same lie and angle and the same length?
"And my coach said 'that's an easy question to ask and a tough one to answer.' So we went on this journey and it's been a great process and a great learning experience for me."
Although DeChambeau faded from contention during the final two rounds in the Middle East, his talent and technique still made a big impression.
"I think he is a really good player and he will blossom and get better," BBC Radio 5 live golf summariser Jay Townsend said. The former European Tour player was speaking after following DeChambeau in his role as an on-course television commentator in Abu Dhabi.
Townsend told BBC Sport: "I think he has a wonderful technique. He has beautiful movement through the ball. You can see that he can play a lot of different shots."
Like most observers Townsend is curious about DeChambeau's club configuration.
"They all have to have the same swing weight, so then the three iron has to weigh more than a normal three iron and then a wedge has to have less mass in the clubhead," he said.
"Then, when you get into the feel shots and the shots out of the rough around the greens you don't have the mass to go through the rough that you really need to play those soft shots.
"Everything is a trade-off in golf. You can't have it all one way, but this is an interesting concept and I'm going to be thinking about it a lot in the next few months.
"I think it has some merit. I'm not sure if I wouldn't make some little tweaks to it, but it's pretty cool.
"No-one is saying he is crazy and there is definitely merit to what he is doing. The theory behind it is very good."
Certainly, given DeChambeau's progress, he has every chance of satisfying his ambition of becoming a trendsetter for the game. He will soon turn professional and there is surely scope for him to create his own range of clubs.
"Amateurs at home will try anything to try to buy a better game," Townsend dryly observed.
It was quite a week for trendsetting in the desert. The European Tour are now allowing their players to wear shorts in practice and pro-ams and Abu Dhabi champion Rickie Fowler's "high-top" golf shoes brought a new look to the course.
Fashions come and go, but a more substantial question surrounds whether DeChambeau has arrived upon a new and lasting way to play the game.


Make no bones about it, the Treasury was behind Martin Wheatley's surprise decision to stand down as the head of the Financial Conduct Authority.

I am told that discussions were held with the head of the FCA in recent weeks where it was made clear that the chancellor would not be asking Mr Wheatley to stay on when his contract came up for renewal in March 2016.
With that sword hanging over his head, Mr Wheatley decided that he would go early.
The Treasury has always had a scratchy relationship with Mr Wheatley who famously said he would "shoot first" and ask questions later when he came across wrong doing in the financial services sector.
The banking industry didn't much like such a gung-ho attitude and Mr Wheatley was often the subject of poisonous comments from senior banking executives.
The FCA also blundered over leaked details of an inquiry into the savings industry. You can read about that shambles here.
Mr Wheatley was very much his own man and he received widespread praise for his aggressive "pro-consumer" attitude - for example leading the charge against the payday loan industry.
The problem seems to be, he wasn't Mr Osborne's man.
So, the Treasury got rid of Mr Wheatley. And it is now becoming clear that the head of the FCA is not happy about that at all.
Talking to those close to the now former head of the FCA, it seems he believes the Treasury was looking for a "big signal" that it was time for a different type of relationship with the City.
Less banker bashing, more supportive of the changes that the City believes it has made on issues of conduct since the financial crisis.
It seems Mr Wheatley did not fit the bill. I asked one person if Mr Wheatley "felt sore" about how he had been treated.
"Oh yes," came the reply.
In the chancellor's Mansion House speech, George Osborne spoke of "a new settlement" with the financial services sector.
Mr Wheatley believed he was talking a similar language, saying that the FCA's aggressive push on conduct issues (look at the large fines for foreign exchange manipulation) had successfully pushed the issue to the level of the board room.
Where it should be, he believed.
It seems Mr Wheatley agreed that the tone and the way of working should now be subtly changed - very much because of the success of the FCA in its more tub-thumping start-up phase (the regulator was formally launched in 2013).
But it appears Mr Osborne did not agree that Mr Wheatley was the man to lead that change.


Broken and vandalised pay and display parking meters are expected to cost Wrexham council around £164,000 in lost income.

The figure was highlighted as the local authority looks to balance its books by the end of the 2016-17 financial year.
The council said some machines had been targeted by thieves earlier this year.
More secure meters are due to be installed which will also accept payment by card and mobile phone, said a spokesman.
The authority has agreed to provide free town centre parking on council-run car parks throughout December for Christmas shoppers.


Margaret Thatcher's premiership was a time of immense social and economic change.

Elected just after the industrial unrest of the "Winter of Discontent", she embarked on a tough reform programme with the top priorities of tackling inflation and the unions.
She presided over a shift from centralised, state-controlled institutions to privatisation and economic reform.
But her policies divided the country as the service sector and home ownership boomed, but manufacturing declined and unemployment rose.
Below are some key indicators of Mrs Thatcher's years in power, May 1979 - November 1990, with the three preceding and following years for context.
One of Margaret Thatcher's first goals was taming inflation which had reached dizzying heights of over 25% in the mid-1970s.
The incoming Conservative government raised interest rates sharply and brought in tough public spending curbs.
A recession followed and unemployment shot up. This also led to reduced wage demands and a slowing of the rate of inflation, although this crept up once more in the boom of the late 1980s.
Unemployment had been rising throughout the 1970s as companies set about restructuring and modernising their businesses.
But it picked up speed after the Conservatives took power in 1979, rapidly rising to over three million out of work in 1983.
Unemployment hit hardest in Northern Ireland, where one in five people was out of work in the early 1980s, along with the industrial areas of northern England and Scotland.
An economic boom later in the decade helped to bring unemployment down, but it was a slow process.
Against this backdrop of high unemployment, the Coal Board announced in early 1984 that 20 uneconomic pits would have to close, putting 20,000 miners out of work.
It was the government's second attempt to close these pits, after a climb-down in 1981.
Miners at the endangered Cortonwood colliery in Yorkshire walked out on 5 March 1984 in protest at the plans. Within a week, more than half the country's miners were on strike.
The dispute lasted a year and led to conflict not only with police but between miners who supported the strike and those who did not.
When the miners returned to work, the pit closure programme continued.
Inflation was running at more than 25% at times in the 1970s, so a key tenet of the incoming Conservative government was to bring it down.
However tough budgetary measures meant that growth suffered in Mrs Thatcher's first term, with a deep recession in the early 1980s followed later in the decade by a boom.
The base rate was then set by the government rather than the Bank of England itself, meaning the government could use it as a tool in their economic policies.
In November 1979, the government raised interest rates to 17% in order to tackle inflation This harmed manufacturing industry and exports, but did eventually have the desired effect on inflation.
However the base rate was pushed up again towards the end of Mrs Thatcher's last term in office to curb inflation, which was stoked by rising house prices.
For Margaret Thatcher, home-ownership was a right, and one which which she believed should be extended to council house tenants.
One of the first acts of her government was to launch a Right to Buy policy which came into force in 1980.
It allowed local authority tenants to purchase their council house at a discount of up to 70%. More than a million took up the offer under her premiership and a version of the scheme is still running today.
As home ownership grew, house prices also rose, climbing 32% in the year to March 1989. This growth would be followed by a slump during the recession of the early 1990s, under John Major's government.


Derby County were beaten in their final game before the Championship play-offs as David McGoldrick's first-half penalty earns Ipswich Town victory.

The hosts failed to create many clear chances in a drab match and had midfielder George Thorne taken off with a serious leg injury late on.
McGoldrick fired in the winner from the spot after Teddy Bishop was brought down in the area by Richard Keogh.
The Rams finish fifth and will host Hull in the first leg of the play-offs.
Derby face the Tigers at the iPro Stadium on 14 May, with the reverse fixture at Hull's KCOM Stadium on 17 May.
Ipswich finish the season a place outside the play-offs in seventh place, five points adrift of Sheffield Wednesday.
The hosts had to play the final eight minutes of the match with 10 men because of Thorne's injury, which he sustained in a challenge with Jonathan Douglas.
Derby head coach Darren Wassall: "I've talked about the importance of the squad and we've got an abundance of midfield players, so if George is seriously injured that's the only shining light we've got.
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"Ultimately this result doesn't matter. In the big scheme of things it's inconsequential because next week's results are the ones that will define our season."
Ipswich manager Mick McCarthy: "It was a good away performance and it's given me a lot of encouragement for next season.
"We've finished on a high, we've played 46 games and there's no point wishing or hoping, that's not me, the reality is we weren't good enough to get into the play-offs."


Tesla reported a loss of $293m (£220m) for the second quarter - the electric car maker's thirteenth consecutive quarterly loss.

Sales for the period from April to June were $1.3bn, which was less than analysts' forecasts of $1.6bn.
Tesla delivered 14,402 cars during the quarter missing its target of 17,000.
It is the second consecutive quarter that Tesla has missed production targets, raising doubts about whether it will reach its full year goal.
Tesla reported that nearly half of its second quarter production occurred in the final four weeks of the quarter.
But the company said it was on track to deliver 50,000 Model S and Model X vehicles in the second half of the year.
New vehicles orders rose by 67% compared to the same time last year.
"Making cars is hard... and they still are in the growth stage. The market seems to want to give [Mr Musk] the benefit of the doubt," said Ivan Feinseth an analyst at Tigress Financial Partners.
Inside Tesla's gigantic Gigafactory
Tesla agrees deal to buy SolarCity
In the second quarter Tesla completed the design work on its Model 3 sedan and intends to start production before the end of the year.
The Model 3 is Tesla's attempt to widen its market appeal with a more affordable car. Its starting price is expected to be $35,000.
The company also plans to add new stores in Taipei, Seoul, and Mexico City along with extra outlets in markets where it already has a presence, such as California.
Tesla's chief executive Elon Musk announced last month plans to expand the company's vehicle line to include electric trucks and buses.
He opened the firm's Gigafactory in Nevada last week which Tesla promises will dramatically lower the cost of batteries for cars.
The BBC's Dave Lee described the factory as "a solid vision of the future of manufacturing" after taking a tour of the facility.
And on Monday, the company announced a deal to buy solar panel company SolarCity for $2.6bn.
Some investors have questioned the viability of the deal as both Tesla and SolarCity continue to report losses.
There were also questions about the close links between the two firms - Mr Musk is already chairman of SolarCity's board and his cousin Lyndon Rive is the company's chief executive.
Once the companies are combined Mr Musk's ownership stake will increase from 23% to 25%, leaving him as the largest shareholder.
He has called the deal a "no-brainer" and said the tie-up would save $150m a year.
SolarCity has until 14 September to solicit offers from other potential buyers.


Swansea City manager Paul Clement has said his side must reflect on the "bigger picture" after their 2-0 defeat by Bournemouth in the Premier League.

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Clement's side dropped to 17th place after the loss and are three points clear of the relegation zone.
The Swans, who have let in nine goals in their past four games, also have the league's worst defensive record.
"Bournemouth have just shown when you put two good home results, it gives them breathing space," Clement said.
"We have to reflect on the bigger picture as well, we started January rock-bottom. We play two home games and we have to respond quickly."
Swansea were bottom of the Premier League when Clement took over in January but have won four of their nine league matches since.
However, they have conceded 63 goals this season - the highest in the league - and have managed just one clean sheet in their last 14 games.
"The fact is, we're 17th, out of the bottom three with two home games coming up. There's lots of football," added Clement.
"We've come a long way in the last two and a half months. We're confident we can still go on and do well this year."
Swansea resume after the international break with a home game against fellow strugglers Middlesbrough, before hosting Tottenham just three days later.


A man has been charged with false imprisonment and wounding after two women were held hostage at a Birmingham charity.

Michal Malecki, 31, of no fixed address, appeared before Birmingham magistrates on Friday.
Two women were held at Bita Pathways offices in Alcester Street, Digbeth for over four hours on Wednesday.
He was remanded in custody and will appear at Birmingham Crown Court on 30 November.
One woman in her 40s was treated in hospital for neck and arm injuries.


Not enough is being done to prevent people leaving the UK to join Islamic State in Iraq and Syria, a group of MPs has warned.

Keith Vaz, chairman of the Home Affairs Select Committee, said Britain must win their "hearts and minds".
The committee's report comes as the BBC launches a database tracking British jihadists in Syria and Iraq.
It shows that many people left in clusters from certain UK areas - often due to friendships and peer groups.
The MPs' report argues that preventative work with communities, families and international partners is "vital" and needs to be a top priority for the Home Office.
"The number of cases being brought to public attention should ring alarm bells," said Labour MP Mr Vaz.
"This must be a relentless battle for hearts and minds, and without a strong counter-narrative we are in danger of failing to prevent even more departures. We are at the edge of a cliff."
The BBC has been tracking the stories of the men, women, boys and girls who have gone to Syria and Iraq to understand why they go, where they go from and what happens to them.
By analysing around 160 profiles, it reveals the way in which people have travelled in clusters - a group of three young friends from Coventry, another group from Portsmouth, drawn out by one person they knew, others in Cardiff linked to people involved in an extremist organisation.
Social media might play a part but face-to-face contact appears just as, if not more, important, according to the database.
It includes the stories of:
The BBC research emphasises the extent to which real-world contacts, rather than just online connections, are often a key driver of radicalisation and intent to travel to Iraq and Syria.
Some of the experts who appeared before the Home Affairs Committee also argued the internet was a secondary influence.
They said that universities and prisons were among the two most significant places where radicalisation occurred.
A spokesman for the Metropolitan Police, which was not aware of the MPs' report, said it would have "welcomed the opportunity" to have given evidence to the committee and that it planned to look at the report in detail.
The disappearance of schoolgirls Shamima Begum, Amira Abase, both 15, and Kadiza Sultana, 16, from east London in February, raised questions as to who could have done more to prevent their departure.
After taking evidence from the police and the families of the girls among others, Mr Vaz said their case suffered from a "lack of immediate action".
He added: "Schools and the police must inform parents immediately, and work with them even if there is the smallest hint of radicalisation, or a close association with someone who is thought to have been radicalised."
However, the Met Police spokesman defended the speed of the police response to the schoolgirls' disappearance.  He said the committee's criticism was "misleading", pointing to the evidence given by both UK and Turkish authorities of "rapid exchanges" between the two.
The committee's report said there needed to be an advice service which would be a less extreme step than calling the anti-terrorist hotline.
The Association of Chief Police Officers lead officer for the government's anti-terror strategy Prevent, Chief Constable Sir Peter Fahy, agreed that more needed to be done.
However, he said the police "do not have the capacity" to routinely work with every school in the country.
He added: "The police service will play its part but the prime responsibility for dissuading young people from getting involved in extremist activity has to lie with parents, families and carers."
The committee also pointed to weaknesses in information sharing with airlines and other countries.
It said greater care needed to be taken at airport check-in desks when people were travelling to destinations of concern - namely Syria, Somalia, Iraq and Nigeria, as well as neighbouring countries, such as Turkey.
The report said police also needed to work faster to alert overseas partners and airlines when there were concerns over individuals.
There were signs that some of the girls had followed extremist accounts on social media, the report said.
The committee said that social media companies, such as Facebook and Twitter, should be prepared to suspend accounts when there is evidence they are being used to promote violent extremism.
The report also said it was disappointed the Home Office had not implemented a programme for individuals returning to Britain where there is evidence they had fought in Syria.
Security officials estimate that some 600 Britons have left the country to join IS - and while around half may have returned, many are still out there - and some have died.
The BBC project includes detailed profiles of individuals which can be searched, based on hometown, age and gender, as well as those who have been convicted in the courts or who are believed to have been killed.
A Home Office spokesperson said: "Our priority is to dissuade people from travelling to these areas of conflict, and the Prevent strategy is working to identify and support individuals at risk of radicalisation. The new legal duties we have introduced on public bodies will help strengthen this work.
"The recent Counter-Terrorism and Security Act has also added measures to disrupt travel, including a new temporary passport seizure power. We continue to work with the airline industry to develop new arrangements to ensure that young people at risk are properly identified.
"It's vital that if families are worried that a loved one may be at risk they should contact the police."


Five teenage girls barred from travelling abroad are pupils at the same east London school attended by three girls already thought to have fled to Syria.

All eight teenagers attend Bethnal Green Academy in Tower Hamlets.
In a decision taken at the High Court, the five girls have been made wards of court and had their passports removed.
The link to the school was revealed after reporters argued it would be in the public interest.
The judge, Mr Justice Hayden, had made an order saying the five girls could not be identified at the High Court in London.
He made a ruling allowing the school to be named at a follow-up hearing in the Family Division of the High Court.
Journalists argued that parents in Tower Hamlets considering schools for their children had a "right to know" whether the three missing teenagers and the five grounded girls went to the same school.
Barrister Christopher Barnes, for Tower Hamlets Council, and barrister Jennifer Carter-Manning, for the Metropolitan Police, argued against naming the school attended by the five girls.
They said revealing the name would pose a risk of the teenagers' identities being revealed - and said the girls could suffer.
However the point was made that staff and pupils at the academy were already likely to know who the five pupils were.
Revealing the name of the school to members of the public outside the school "community" would not create a significant risk of the girls being identified, it was argued.
Mr Justice Hayden ruled in favour of the press.
The five girls - two aged 15 and three aged 16 - were barred from travel after showing an interest in going to Syria.
Mr Justice Hayden made the move to bar travel following an application from Tower Hamlets social services officials.
He was told that social workers had raised concerns that the girls might flee to areas controlled by Islamic State (IS) and he said sometimes the law had to "intervene to protect young people from themselves".
The judge has continued to analyse the girls' cases at further hearings - and has heard evidence from counter-terrorism specialists at the Metropolitan Police.
A number of adults involved in their care have also had their passports seized.
There was evidence to suggest family members in the case had not been "full and frank" with social services, the judge said, and that the girls were becoming "more radicalised".
In mid-February police raised concerns following the disappearance of Kadiza Sultana, 16, Shamima Begum, 15, and Amira Abase, 15, from their homes in east London.
Shamima used the passport of her 17-year-old sister to leave the UK, police have said.
The three girls were friends and pupils at Bethnal Green Academy.
A fourth girl from the same school, Sharmeena Begum, 15, from Bethnal Green, left about two months before the three girls.
All four teenagers are thought to be in Raqqa - the Syrian city where IS has its headquarters.


Carlisle United striker Jabo Ibehre has had the red card he received after 34 seconds against Accrington overturned.

Ibehre was dismissed for a high boot on Matty Pearson but an FA panel rescinded the sending off after a club appeal.
"It goes without saying that we think the correct outcome has been reached," boss Keith Curle told the club website.
"Ultimately we had to play over 90 minutes with only 10 men, but that's been and gone now. The positive to come out of it was how the team responded."


Mae un o'r newyddiadurwyr mwyaf profiadol o Gymru wedi mynegi ei siom bod newyddion ffug yn arwain at "ddiffyg ymddiriedaeth mewn newyddion".

Fe wnaeth Stephen Evans adael y BBC yr wythnos hon ar ôl bron i 30 mlynedd gyda'r gorfforaeth.
Yn wreiddiol o Sir Benfro, mae wedi bod yn gweithio fel newyddiadurwr ers bron i 40 mlynedd, a bydd nifer yn ei gofio fel un o brif leisiau'r BBC yn dilyn ymosodiadau terfysgol 9/11 yn 2001.
Yn gweithio fel gohebydd busnes Gogledd America ar y pryd, roedd ar lawr gwaelod y World Trade Center pan wnaeth yr awyren gyntaf daro'r adeilad.
Bu wedyn yn cyfrannu'n helaeth i gynulleidfaoedd Radio Cymru a Newyddion 9 dros y dyddiau wedi hynny, yn ogystal â nifer o wasanaethau eraill y BBC.
Bu'n rhannu ychydig o'i hanes fel newyddiadurwr, a'r hyn sydd wedi newid dros y pedwar degawd diwethaf, gyda Cymru Fyw:
"Fe wnes i hyfforddi ar y Western Telegraph, a phan ddechreues i roedd papurau newydd yn rhan enfawr o fywyd Cymreig," meddai.
"Roedd gan y Western Telegraph ddau bapur pan oeddwn i'n dechrau yn Hwlffordd, ond mae llawer o hynny wedi mynd erbyn hyn.
"Byddai pawb yn Sir Benfro yn darllen y Telegraph, ac roedd pobl yn llythrennol ar bigau drain i'w gael o. Byddai pobl yn disgwyl amdano.
"Roedden ni'n gwneud ysgrif goffa am bron i bawb fyddai'n marw yn y sir.
"Roedd hyfforddi i fod yn ohebydd bryd hynny yn wych - fyddech chi ddim yn meiddio cael pethau'n anghywir, oherwydd os byddai gennych chi wallau byddai pobl yn llythrennol yn dod i mewn i'r swyddfa a chwyno."
Ymunodd â'r BBC gyda Radio 4 yn 1988, cyn symud i fod yn ohebydd. Yn fwy diweddar mae wedi bod yn ohebydd yn Berlin a Seoul.
Ond dyw Stephen ddim yn hiraethus am bob agwedd o newyddiaduraeth pan oedd yn ifanc, gyda datblygiadau bellach yn ei gwneud yn haws darlledu o unrhyw le yn y byd.
"Mae'n hawdd dweud bod pethau cymaint gwell yn yr hen ddyddiau, ond mewn gwirionedd mae technoleg wedi gwella pethau'n anferthol," meddai.
"Ar gyfer teledu er enghraifft, os oeddech chi eisiau gwneud darn byw byddech chi angen tryciau o offer, llawer o bobl a mynydd o waith paratoi.
"Ond nawr, rydw i wedi gwneud darnau byw o Pyongyang yng Ngogledd Corea ar fy ffôn. Mae'n newid aruthrol."
Un peth sydd wedi siomi Stephen gyda'r diwydiant dros y blynyddoedd diweddar yw newyddion ffug, ac mae'n dweud, er ei holl fuddiannau, bod y we wedi cyflwyno ei hun fel llwyfan i unrhyw un rannu newyddion, boed yn wir ai peidio.
"Yr hyn sydd hefyd wedi newid dros fy nghyfnod i, yn amlwg, yw newyddion ffug a diffyg ymddiriedaeth mewn newyddion," meddai.
"Pan oeddwn i'n dechrau, mewn llefydd fel Hwlffordd neu Gastell-nedd lle oeddwn i, roedd pawb yn derbyn eu newyddion gan ffynonellau y gellir ymddiried ynddynt
"Roedd pawb yn darllen y Western Mail. Radio Wales a Radio Cymru oedd prif ffynonellau gwybodaeth. Felly roedd rhyw fath o gysondeb i ddaliadau gwleidyddol pobl. "Doedden nhw ddim yn cael daliadau gwallgof o bob cornel o'r byd.
"Y syniad oedd y byddai'r we yn gwneud newyddion yn fwy democrataidd ond mewn gwirionedd, mewn ffordd mae'n tanseilio democratiaeth. Mae hynny'n newid enfawr.
"Mae'n welliant mewn nifer o ffyrdd - y dechnoleg sydd mor ystwyth - ond gall fod yn beryglus iawn, bod llwyfan i bob mathau o syniadau hurt a ffals - pobl yn gwneud drygioni ac yn gwasgaru celwyddau."
Ai dyma'r diwedd i newyddion traddodiadol felly? Yw'r cyfryngau cymdeithasol wedi gwneud hynny'n ddiangen?
"Dydw i ddim yn ddigalon am ddyfodol newyddiaduraeth," meddai Stephen.
"Rwy'n meddwl bod papurau newydd nawr yn sylweddoli, dydyn nhw ddim wedi marw.
"Yr hyn rwy'n gobeithio fydd yn digwydd yw y bydd pobl yn dechrau sylweddoli eu bod angen ffynonellau gwybodaeth y gellir ymddiried ynddynt, a bydd ffynonellau fel y BBC yn gwbl ganolog i hynny.
"Wrth i bobl sylweddoli bod celwyddau a drygioni allan yno, ac ni allwch chi o reidrwydd goelio yr hyn dy'ch chi'n ei weld o'ch blaenau, bydd pobl yn gweld mai nonsens yw'r cwbl."
Ond dyw Stephen ddim wedi'i ddadrithio gan newyddion a newyddiaduraeth, ac yn wir, nid ymddeol yw ei gynlluniau.
Mae'n symud i Awstralia i weithio fel gohebydd i bapur newydd bychan sy'n cael ei gyhoeddi pob pythefnos, mewn ardal ddiarffordd rhyw naw awr o yrru o Sydney.
"Roeddwn i wastad wedi bod eisiau mynd i Awstralia fel tipyn o antur am 'mod i mor hoff o'r lle, ac maen nhw wedi cynnig swydd i mi," meddai.
"Mae'r papur newydd yn meddwl 'Sut yn y byd allwn ni ddelio â'r byd newydd yma?' felly efallai y gallai eu helpu gydag ychydig o'm mhrofiad i."


Specialist doctors will be able to examine more patients in rural mid Wales without long distance travel in a new £250,000 technology scheme.

Telehealth services are being explored by health and social care professionals aiming to improve rural treatment.
Health Minister Mark Drakeford said orthopaedic specialists in Abergavenny could already look at X-rays from Brecon, reducing patient travel.
He said the project would allow more people to be treated closer to home.
Telehealth is a way of treating of patients in remote areas in a separate location from the clinicians.
People with long-term conditions can also monitor themselves at home using technology rather than going into hospital.
The money comes from a £10m fund to promote efficiency through technology in the Welsh NHS announced in January.
"This investment will take stock of all practices which use telehealth across NHS Wales and look at how, within the Mid Wales Healthcare Collaborative region, we can scale these projects up to benefit more patients," Mr Drakeford said.
"This funding will increase the number of people who can benefit from this kind of technology, ensuring they receive care closer to home."


Five female Pakistani polio vaccination workers have been fatally shot in a string of co-ordinated attacks - four within 20 minutes across Karachi.

The fifth woman was shot and wounded in the city of Peshawar in the north-west and later died of her injuries.
A UN-backed programme to eradicate polio - which is endemic in Pakistan - has been suspended in Karachi.
No group has said it carried out the shootings, but the Taliban have issued threats against the polio drive.
"These were pre-planned and co-ordinated attacks in various localities which took place within a span of 20 minutes," Imran Javed, a police spokesman told the BBC of Tuesday's attacks in Karachi.
Earlier reports said a male health worker had been shot dead in Karachi on Monday, but officials now say his death was not related to the polio vaccination drive.
Prime Minister Raja Pervez Ashraf has condemned the attacks and praised the work of the polio vaccination teams, calling on regional authorities to guarantee their safety, Pakistan's APP news agency reported.
Pakistani health officials said the latest three-day nationwide anti-polio drive - during which an estimated 5.2 million polio drops were to be administered - had been suspended in Karachi, Pakistan's largest city with a population of 18 million.
Source: IMB
There has been opposition to such immunisation drives in parts of Pakistan, particularly after a fake CIA hepatitis vaccination campaign helped to locate Osama Bin Laden in 2011.
Militants have kidnapped and killed foreign NGO workers in the past in an attempt to halt the immunisation drives, which they say are part of efforts to spy on them.
However, the Pakistani government "would continue to mount its effort on polio eradication," Mr Ashraf's special adviser Shahnaz Wazir Ali told the BBC.
By M Ilyas KhanBBC News, Islamabad
The price of polio prevention
Mrs Ali said protection would be provided to workers, and campaigns would be staggered if necessary.
"Clearly, we are now so close to eradicating the polio virus,... acts of this type, which are intended to dissuade us, will not deter us," she said.
Along with Afghanistan and Nigeria, Pakistan is one of only three countries where polio is still endemic.
Pakistan is considered the key battleground in the global fight against the disease, which attacks the nervous system and can cause permanent paralysis within hours of infection.
Almost 200 children were paralysed in the country in 2011 - the worst figures in 15 years.
Earlier this year, the Global Polio Eradication Initiative warned that tackling the disease had entered "emergency mode" after "explosive" outbreaks in countries previously free of polio.
The World Health Organization (WHO) said polio was at a tipping point, with experts fearing it could "come back with a vengeance" after large outbreaks in Africa and Tajikistan and China's first recorded cases for more than a decade.
Declaring polio a national emergency, the Pakistani government is targeting 33 million children for vaccination with some 88,000 health workers delivering vaccination drops.
Dr Bruce Aylward of the WHO told the BBC that vaccination programmes had been suspended in other countries before but that "when you're dealing with something as basic as the health of children, usually there can be common ground found".
Dr Aylward said he hoped for a "dialogue with community leaders who have positions of power to ensure root causes of this are being addressed and the perpetrators are brought to justice".