Three missing Bradford sisters feared to be trying to get to Syria with their nine children were stopped before an earlier flight, the BBC understands.

Sources said Khadija, Sugra and Zohra Dawood and their children missed a flight to Saudi Arabia in March after being questioned by security officials.
However, they were subsequently cleared to travel and rebooked their flights.
Earlier, police revealed one of the women has "made contact" with family, indicating she may already be in Syria.
The BBC understands middle sister Zohra Dawood, 33, got in touch with relatives in the UK to say she was in Syria.
The women's brother, Ahmed Dawood, is believed to be fighting with extremists in the country, parts of which are controlled by Islamic State militants.
The Dawood sisters and their children were originally booked to fly from Manchester to Jeddah for a religious pilgrimage on 19 March.
The flights were arranged via a Bradford travel agent and a company in London. The BBC has seen documents confirming the intended travel.
However, the extended family were stopped by security officials and questioned, causing them to miss their flight.
Police have special powers at airports to stop and question travellers on suspicion of involvement in terrorism.
The BBC has also spoken to the taxi firm which collected the party from the airport in March, who confirmed they were told the women and children returned home without catching the flight.
Days later, the family rebooked flights, telling their travel agent they had cleared the matter up after discussions with the police.
However, because of the size of the party and the Easter holidays, the women were unable to book another departure date until May.
They eventually left Manchester Airport on 28 May and were due to stay in Saudi Arabia until 11 June. However, they left on 9 June and took a flight to Istanbul instead.
The BBC understands they told the manager of their accommodation on 9 June that they intended to travel to Mecca before returning to the UK, and left taking the keys to their rooms.
In a statement to the BBC, the North East Counter Terrorism Unit said: "The North East CTU can confirm that the same group were stopped and subject of security checks earlier this year.
"As a result, enquiries revealed that the visit was a religious pilgrimage to Saudi Arabia and the group were not prevented from travelling. However the process of conducting those enquiries caused the group to miss the flight.
"On a daily basis a number of people are subject to security checks prior to boarding flights.
"It is worth repeating that the party were not legally prevented from travelling."
by BBC Middle East correspondent Paul Wood, in Turkey
Smugglers on the border told us the jihadis had one illegal border crossing still working. A smuggler called Abu Ahmed said he guided people in through the wire for the equivalent of Â£5 each.
Sometimes that price goes up when there are more guards on the border, he told me. But it's not difficult, you just wait for a shift change. You still have to pay a bribe. The Turks take a cut.
It's easy then for people heading to the so-called caliphate to get in. It is difficult and dangerous to get out.
A Syrian activist told me there were as many as 200 women - widows of jihadis or those not yet married - under house arrest in the heart of Islamic State territory.
The Bradford families may find they have bought a one-way ticket.
The BBC's security correspondent Gordon Corera said there were questions about how strong initial suspicions were, and why the group were able to travel a few months later.
"However, from a police point of view, it is difficult. They have limited powers, and they would not want to be seen to harass people going on a religious pilgrimage," he said.
West Yorkshire Police says it is "extremely concerned" for the group's safety after receiving information that at least one of the women may have crossed the border into Syria - parts of which are controlled by Islamic State militants.
Assistant Chief Constable Russ Foster said: "We have received information that contact has been made with the family in the UK which suggests one of the missing adults may be in Syria.
"Contact has been made by one of the missing women and there is an indication that they may have already crossed the border into Syria but this is uncorroborated."
Metropolitan Police Commissioner Sir Bernard Hogan-Howe said it was "almost impossible to believe" there were "mums who've taken their children to a war zone".
It has also emerged that the mothers had no authorisation from education authorities to take their children out of school prior to the trip.
Talwinder Bhambra, acting headteacher of Marshfield Primary School, which some of the children attended, said: "We are obviously deeply concerned about the missing children and we are doing everything we can to assist the police and to support the affected families."
Meanwhile, the estranged husband of one of the sisters spoke publicly for the first time.
Syed Zubair Ahmed, the estranged husband of Zohra Dawood and father of two of the missing children, told the BBC from Pakistan he was "shocked" by the news of his wife's disappearance.
He said he left the UK seven months ago after his wife "shunned" him, and had not spoken to her since.
He had not had any indication his wife might be considering attempting to travel to Syria, he said, and her brother had seemed like a "nice guy". He also spoke of his hopes that the UK government would do all it could to bring the family back home.
The husbands of the other two sisters made an emotional appeal on Tuesday, saying they "miss and love" them.
They said they last spoke to their children on 8 June.
West Yorkshire Police has been working with the extended Dawood family and the Turkish authorities to try to establish the group's whereabouts.
They said anyone who was concerned that a family member may be contemplating travelling to Syria should contact police and partners via the free phone Anti-Terrorist Hotline number on 0800 789 321.


Drivers are being warned not to stop if an unmarked police car tries to get them to pull over after two vans were stolen by fake officers.

Essex Police issued the warning after the vehicles were stopped on the M11 and the M25 recently and stolen.
The thieves, dressed in police uniforms and, in one incident, carrying a handgun, used blue flashing lights.
Officers have been told they should not pull people over when in unmarked cars unless it is an emergency.
Follow updates on the latest news from Essex
Det Ch Insp Stuart Smith said: "We have taken this decision to safeguard motorists in Essex while these offenders remain outstanding.
"Our victims have told us that the suspects are purporting to be police officers and are wearing body armour to further enhance this deception in order to steal these vans.
"Anyone who is signalled at to stop by someone in a car which may appear to be an unmarked police is asked not to stop but to call 999 immediately to verify whether the vehicle and its occupants are genuine."


A doctor has been jailed for 27 months for seriously injuring two people in a crash while over the drink-drive limit.

Gwyn Haydn Roberts, 45, drank one-and-a-half litres of cider and two cans of Special Brew after a visit to his sick mother in Gwynedd ended in a row.
Mold Crown Court heard he drove on the wrong side of the road and went around bends on a grass verge on the A487.
Roberts, from Abergavenny, admitted causing serious injuries by dangerous driving.
He was also banned from driving for four years.
The court heard the head-on crash happened on 17 June between Penrhyndeudraeth and Maentwrog in Gwynedd when Roberts crossed a double white line and hit a car.
Two men in that car suffered broken bones, deep cuts and bruises while Roberts' sternum was broken.
Blood tests taken from Roberts four hours later showed he had 180mg of alcohol in 100ml of his blood. The legal limit is 80mg.
Judge Rhys Rowlands said the decision to try and drive more than 130 miles along "tortuous roads" was "extraordinarily dangerous".


Macclesfield Town will host Wrexham in the National League on Tuesday, 27 September, with kick off at 19:45 BST.

Tuesday's match between the two sides was postponed because of a waterlogged pitch at Moss Rose.
A torrential downpour just over an hour before the scheduled 19:45 BST kick-off time left large sections of the pitch under water.
Referee Steve Rushton waited until 18:45 BST before deciding there was no chance of any play.


Prosecutors have failed in a legal bid to bring a new case against a man who was cleared of murdering a 19-year-old student more than 20 years ago.

The Crown Office wanted to use double jeopardy legislation to secure a retrial of Francis Auld over the death of Amanda Duffy in Hamilton.
Her body was found on waste ground in the South Lanarkshire town in May 1992.
Judges at the Court of Criminal Appeal in Edinburgh rejected an attempt by prosecutors to submit new evidence.
Proceedings in the case were heard by Lord Carloway, Scotland's most senior judge, Lord Bracadale and Lady Dorrian.
The Crown wanted to rely on a conversation between prison officer Alexander McCartney and Mr Auld which took place sometime in June 1992.
Mr McCartney spoke to the police in 2012 after investigators learned that he had information which could help their case.
Mr McCartney claimed that Mr Auld - who was on remand at the time at HMP Longriggend in Lanarkshire in June 1992 - made a remark which could be construed as being a confession.
In a legal statement, Mr McCartney told investigators that he started his conversation with Mr Auld by saying: 'It's quite a heavy charge you're in for."
Mr Auld allegedly replied: "We were just fooling about and things got out of hand."
Mr McCartney told the police that he reported this to his superiors. He was told by his supervising officer: "It's just hearsay Alex. There's nothing you can do about it."
The judges ruled that the new evidence was not admissible and could not be used against Mr Auld and the case could not go ahead.
The judges said that the alleged admission of guilt was not made in accordance to laws regarding confessions.
The judges also ruled that because the DNA evidence from the original trial had now been destroyed, the Crown could not bring Mr Auld to court for a second time.
In the judgement, Lady Dorrian wrote: "The case is one which caused great distress to the family of the deceased and shock within the community.
"The court must look at the evidence upon which the application is based and the evidence led at the trial.
"It cannot be swayed by considerations of other, possibly strengthening evidence which may be in the hands of the Crown but which has not formed the basis of an application."
Prosecutors had attempted to use the Double Jeopardy (Scotland) Act 2011 against Mr Auld.
The act allows the Crown to bring a person previously acquitted of murder to court for a second time.
The legislation sets out conditions where an accused can be retried for a crime in which they were previously acquitted.
Any retrial requires high court judges to give prosecutors permission to proceed against the accused.


South Africa's deputy finance minister has confirmed reports alleging that he was offered the position of finance minister by a member of the wealthy and controversial Gupta family.

Mcebisi Jonas says he rejected the offer, calling it "a mockery of our hard-earned democracy".
The opposition has long accused President Jacob Zuma of letting the Guptas wield excessive influence.
The Indian-born family has built up holdings in mining, travel and media.
The Guptas, whose forebears arrived from India in 1933, also have huge interests in computers, air travel, energy, and technology.
They said Mr Jonas' statement was political point-scoring.
In 2013, there was an outcry after a private jet carrying guests to the wedding of a Gupta family member was allowed to land at a South African military air force base in Pretoria.
The opposition has said that links between President Zuma and the Guptas were so close that they have been nicknamed the "Zuptas".
Analysis: Milton Nkosi, BBC News, Johannesburg
The allegations, confirmed by a serving minister, may well represent the lowest point of Mr Zuma's presidency, which has already been beset by multiple corruption scandals.
South Africans have reacted with shock and dismay. Some are already calling for the president to resign.
It is very difficult to see how President Zuma can come out of this latest scandal unscathed.
The ANC's national executive committee's meeting this weekend will face a tough decision: should it keep President Zuma as head of state?
Mr Jonas' shock statement follows questions about the role of the Gupta family in parliament.
He said that "no-one apart from the president of the Republic appoints ministers.
"The narrative that has grown around the issue of 'state capture' should be of concern to all responsible and caring South Africans."
Mr Jonas said he was offered the job of finance minister in December 2015 just before Nhlanhla Nene was sacked by President Zuma.
Mr Zuma then appointed the little-known David van Rooyen, leading to a run on the currency and national protests.
Just days later, Mr Zuma made an about-turn and replaced Mr Van Rooyen with the widely respected Pravin Gordhan.


A call backed by actor Stephen Fry for the return to Greece of the British Museum's Parthenon Marbles has come out on top in a debate held in London.

Fry said it would be a "classy" move to restore the sculptures brought to the UK by Lord Elgin in the 19th Century.
The debate, hosted by Intelligence Squared, ended with a majority for the motion of 384 to 125.
Opposing the motion, Tristram Hunt MP said the British Museum played a key role in cosmopolitan culture.
The Greeks were a proud people suffering terribly, Stephen Fry told the audience in London's Cadogan Hall, but "no matter how much the sovereign debt crisis means they owe us, we will never repay the debt that we owe Greece."
He said he revered the British Museum as "one of the great flowerings of the Enlightenment" but that returning the Marbles to Greece would be an act of "grace and decency".
He said it would be "classy" if future visitors to the British Museum could see a "Parthenon experience" including a film showing how Britain had curated the marbles "beautifully" for 200 years and then handed them over to Athens' Acropolis Museum.
Mr Hunt supported the argument advanced by the British Museum, which says there is a need for collections like its own which allows many different cultures to be compared.
The museum says the division of the sculptures between London and Athens "allows different and complementary stories to be told about the surviving sculptures, highlighting their significance within world culture and affirming the place of Ancient Greece among the great cultures of the world."
It should be a source of pride to the Greeks that the sculptures, as a symbol of Greek culture, were such an important part of the British Museum's collection where it could be compared with exhibits from other civilisations, said Mr Hunt.
He feared that restoring the Marbles could lead to a "purge" of museums in which "tit-for-tat recoveries" of objects by their countries of origin would lead to a "global loss of appreciation and understanding".
He said the Marbles had been legally acquired with a permit from the Ottoman empire and the Greek government had never challenged their ownership in an international court.
But Stephen Fry said the argument did not apply because Greece was an occupied country at the time.
Proposing the motion to send the sculptures back, Andrew George MP said it may be that Elgin helped preserve the sculptures, but that job was done now.
He said he was "appealing to Britain's better instincts" and that restoring the sculptures willingly now would be better than a "cringing climb-down" some time in the future.
The debate comes a week before an "International Colloquy" in London on the Parthenon sculptures in London, organised by the British, US and Australian committees calling for their return to Greece. Those attending will hold a "planned organized attendance" at the British Museum on 20 June.
Recordings of the debate will be broadcast on BBC World News at 09:10 and 21:10 on 23 June, and 02:10 and 15:10 on 24 June. All times GMT.


Hibernian have signed former Fulham and Bristol City defender Liam Fontaine on a one-year deal.

The 28-year-old centre-half was released by the Robins at the end of last season, having signed on at Ashton Gate in 2006.
Fontaine's arrival coincides with the departure of defender Michael Nelson, who has joined Cambridge United.
The 34-year-old joined Hibs 12 months ago from Bradford City and played in the club's last two matches.
Fontaine, who played in Scotland previously on loan to Kilmarnock from Fulham in 2005, is available to face Dumbarton in the League Cup on Tuesday evening.
While at Craven Cottage, he was also farmed out to Yeovil Town and Bristol City.
That latter switch led to permanent transfer and he went on to make 279 appearances for the Robins.
However, he spent five games back on loan from the English League One club to Yeovil last season as the Glovers were relegated from the Championship.
"Liam is a real quality signing, who will undoubtedly add a huge amount to the squad and further strengthen our defence," said Easter Road manager Alan Stubbs.
"We did our homework on him - both as a player and as a person - and he ticked all the right boxes and he has immediately bought into what we're trying to achieve at the club."
Nelson, previously of Norwich, Scunthorpe and Kilmarnock made 39 appearances for Hibs and scored three goals for the club.


The head of the Bangladesh Cricket Board has said he is confident there "won't be any problem" with security when England tour there this autumn.

The England and Wales Cricket Board (ECB) announced the tour would go ahead after conducting a security review.
Nazmul Hasan Papon, president of the BCB, has offered security for players, fans, family members and media.
He said no nation is "100% safe" but no other country's board "provides such security".
England will play two Tests and three one-day internationals between 7 October and 1 November.
"The security aspect, well it's almost the same everywhere," Papon told reporters in Bangladesh. "One can't say that any country in the world is a 100% safe. It can happen anywhere.
"However, the security plan that we gave them and the Bangladesh government is providing, I don't think any other board provides such security.
"Lastly, when we handled so many teams during the Under-19 World Cup, I don't think it will be difficult to handle one team for our security agencies. So I was confident that they would come."
Papon also said safety would be provided not just to the England team, but to all those travelling as part of the tour, including relatives, supporters and media.
"We will make sure that not just the players but the fans, the family members, the reporters - if they let us know as to where they stay and they contact us, we will arrange security for them no matter where they are, be it in the stadium or next to the hotel, wherever," he said.
"We believe that there won't be any problem with regards to this England tour."
England's matches will take place in Chittagong and Dhaka, where 20 hostages died when a cafe was attacked in July.
On Saturday, Bangladeshi police said they had stormed a hideout near Dhaka and killed the suspected planner of that attack.
Australia postponed their Test tour of Bangladesh in October 2015 over security concerns.


Turkish Prime Minister Ahmet Davutoglu has confirmed that the Turkish military has attacked Kurdish fighters in northern Syria.

The Kurdish People's Protection Units (YPG) said Turkey shot at its forces in the town of Tal Abyad on Sunday.
The YPG has been a key ally of the US in fighting the so-called Islamic State (IS) group in Syria.
Turkey fears advances by the YPG near its Syrian border could fuel separatist sentiments amongst Kurds in Turkey.
The attacks come amid increasing tensions in Turkey ahead of elections.
"We said the [YPG-aligned Democratic Union Party] PYD will not go west of the Euphrates and that we would hit it the moment it did," Mr Davutoglu told Turkish ATV television late Monday.
He gave no further details.
It is not the first time the YPG has said Turkey has attacked them. In July they said Turkey had shelled them in the Kurdish-held village of Zormikhar, which Turkey denied.
In a separate incident, Turkey has confirmed detaining 30 IS militants during a dawn raid on Tuesday.
Police conducted simultaneous operations against IS cells in the central Anatolian city of Konya and the nearby town of Cumra, the Dogan news agency reported.
It comes a day after a deadly shoot-out with suspected IS militants in the city of Diyarbakir on Monday which left two police officers and seven militants dead.
Another five officers were injured and 12 militants were detained, Deputy Prime Minister Numan Kurtulmus said.
AFP news agency said this was the first clash with IS militants on Turkish soil since Turkey launched air strikes on IS targets in Syria in July.
Turkey has stepped up operations against IS since the group was blamed for twin blasts that killed more than 100 people in Ankara this month.
Tensions are running high in Turkey just five days ahead of general elections.
The double bombing in Ankara - targeting a Kurdish peace rally - was the country's most deadly, and came amid an upsurge of fighting between Turkish forces and Kurdistan Workers' Party (PKK) rebels.
Prime Minister Davutoglu said the bombings were an attempt to influence the 1 November elections.
Many of the victims were activists of the pro-Kurdish HDP party, which believes its delegation at the rally was specifically targeted.


Tiger Woods says he is setting up for "phase two" of his life as he returns to the PGA Tour for the first time in 15 months at the Hero World Challenge.

Media playback is not supported on this device
The 40-year-old, who has fallen to 898th in the world, will take part in the 18-man tournament in the Bahamas, which begins on Thursday.
Woods has not played on the PGA Tour since August 2015, twice undergoing surgery due to ongoing back problems.
"I want to play for a lifetime, but I can't compete for a lifetime," he said.
Woods, who has spent time during his injury lay-off working on other business ventures, added: "I call it phase two, because I can't play this game forever at a competitive high level.
"Would I love to? Yes. Guys have played into their 70s and 80s but they're not competing at a world-class level."
However, Woods, who will head out alongside fellow American Patrick Reed, says he will be targeting a win at Albany this weekend.
"They're going to try and beat me. I want to beat them, too," he added. "If I enter an event, I'm going to try and win the thing. I know that's a tall order, but the mindset is still there."
A vice-captain for the United States team that won the Ryder Cup in October, Woods missed the whole of the 2015-16 season through injury.
The 14-time major champion played in 11 tournaments the previous season, with his last appearance coming at the 2015 Wyndham Championship where he tied for 10th.
Woods, who has won 79 titles on the PGA Tour, has not had a tournament victory anywhere since 2013 and his title drought in the major championships dates back to 2008.
Media playback is not supported on this device
"To get back out here at this level has been a challenge," added Woods. "A lot of hard work and an inordinate amount of patience, which is not one of my hallmarks.
"It's allowed me to get to this point where I am able to compete and able to play. I haven't had adrenaline in my system for a while. As of right now, I'm ready to go."
Woods, whose charity foundation owns the event, called the sport a "fraternity" and said his fellow professionals have helped aid his return "in any way possible".
He was due to play in the Safeway Open in California last month, but delayed his comeback after claiming his game was "vulnerable".
"As a competitive athlete it killed me inside," said Woods about his withdrawal.
"I wanted to compete. I'd waited at the time for 13 months - let's be patient, a little easier on myself, smarter.
"It gave me a couple more months to get stronger."


A decision to transfer Suffolk's 16 local authority care homes to a private firm has been endorsed after Labour opponents called it in.

The Conservative-run council's plan is to hand the centres to Care UK, which would then build 10 replacement homes.
Labour councillors claimed financial information was inadequate and asked the scrutiny committee to look at it.
Committee members upheld the original decision, saying it was not convinced by Labour's arguments.
The transfer of the homes was due to take place on 1 November before the decision was called in.
Councillor Colin Hart, Conservative chairman of the scrutiny committee, said: "The majority of the committee was not convinced by the 'call-in' argument that the information available to the cabinet, when they took their decision, was inadequate."
A new date for the transfer has yet to be set.
The council said Care UK would be investing Â£60m in building the new homes, with construction beginning next year.


A prison nurse who smuggled a mobile phone into jail in order to exchange sexual text messages with an inmate has been jailed for 20 months.

Elizabeth Hutton gave Medi Abalimba the phone while he was serving a sentence for fraud at HMP Moorland, near Doncaster, Sheffield Crown Court heard.
She also gave him a pair of knickers and a "provocative" photo of herself.
The relationship came to light after colleagues became suspicious of 50-year-old Hutton's behaviour.
On one occasion she hung a "Do not disturb" sign outside a consultation room, the court was told.
Following that encounter, Abalimba was found to be in possession of a black Samsung mobile phone.
More stories from across Yorkshire
During a subsequent search of his cell, a cardboard box containing the underwear and photograph was found under his bed.
When the police examined a phone previously seized from Abalimba they found "a series of increasingly intimate and sexual messages" sent between the prisoner and Hutton.
Hutton, of Kingsley Avenue, Wakefield, pleaded guilty to charges of misconduct in a public office and conveying a prohibited article into prison.
Her barrister Ian Howard said his client had been "in a vulnerable position" and suffering from low self-esteem as a result of large debts she had accrued following her divorce in 2005.
He said Abalimba, who was jailed in 2014 for impersonating Chelsea footballer Gael Kakuta, was a "skilled confidence trickster".
"He used his charm on this vulnerable woman to persuade her to do what it was that he wanted," said Mr Howard.
Jailing Hutton, Judge Julian Goose said: "Your obligation was to provide a professional medical service for serving prisoners.
"The public was entitled to expect you would perform that duty.
"To form an inappropriate relationship with a serving prisoner was plainly a breach of that obligation."


Chelsea midfielder Cesc Fabregas has rejected suggestions of a bust-up with manager Antonio Conte.

The manager was reported to be open to allowing 29-year-old Fabregas to leave before the transfer deadline.
Fabregas, however, has posted on social media that the pair have a "good relationship" and that he is "fully committed" to the club.
"Contrary to what has been written, the manager has never told me that I can leave," Fabregas wrote.
"He said that he counts on me, as I count on him. I will continue to fight for this club until the very end and when called upon I will always give my very best.
"I'm fully committed to Chelsea FC and my only goal is to help them win more trophies."
The former Barcelona and Arsenal midfielder has made 97 appearances for Chelsea but was an unused substitute for their 3-0 Premier League win over Burnley on Saturday.
Subscribe to the BBC Sport newsletter to get our pick of news, features and video sent to your inbox.


Hollywood A-lister Gerard Butler will feature in a documentary being shown at the Cannes Film Festival about the Scottish charity Mary's Meals.

The Scots actor appears in Generation Hope, which focuses on the charity's projects in Malawi, Haiti and India.
The 30-minute film, by US director Charles Kinnane, will be exhibited at the festival's Short Film Corner.
Mary's Meals now feeds more than one million of the world's poorest children every day they attend school.
Butler has supported Mary's Meals for several years and has visited one of its sites in Liberia.
He previously appeared in a short film about the charity's work, titled Child 31.
Mary's Meals was born in 2002 when Magnus MacFarlane-Barrow, from Argyll, visited Malawi and witnessed the plight of youngsters there who did not have enough to eat.
Mr MacFarlane-Barrow said: "When we were filming Generation Hope we couldn't have imagined it would enjoy the exposure offered by such a high-profile international event.
"It's an incredible gift to bring our work to new eyes, new ears and new hearts in this way."
Describing what the film is about, he said: "Children who used to miss school are now in classrooms, children who were once too hungry to concentrate can now learn, children who used to be unhappy are laughing in their playgrounds, and children who were resigned to having no energy are chasing footballs.
"Now we see that a beautiful revolution is taking place as a new generation, once fed by Mary's Meals, begins to find its voice.
"We call them 'Generation Hope' and this is what this film is about - the university students, singers, farmers, teachers, DJs, footballers and other young people who, well-nourished and well-educated, are now finding their own way in life."
Generation Hope will be shown at the Cannes Film Festival in May.


South Sudan's capital, Juba, remained tense on Saturday, the fifth anniversary of its independence, after deadly clashes between rival factions.

Juba is in lockdown amid fresh fighting, apparently sparked by a shootout between the bodyguards of the leaders of the two factions. Some reports speak of dozens dead.
President Salva Kiir and Vice-President Riek Machar have both called for calm.
A 2015 peace deal to end a 20-month civil war has failed to quell unrest.
'We want peace - and ice cream'
The latest clashes came after Mr Kiir and Mr Machar met at the presidential palace on Friday.
A half-hour shootout among bodyguards escalated into heavy weapon and then artillery fire in several parts of the city.
A doctor at a hospital told the Associated Press that soldiers had brought in scores of bodies, most of them military men, but this has not been independently verified.
An earlier deadly altercation on Thursday night left five soldiers dead at a checkpoint.
Mr Kiir and Mr Machar described Friday's violence as "unfortunate".
The rival armed factions both took up positions in April as part of the peace deal, which saw Mr Machar return to the country.
Tens of thousands died in the civil war and millions were forced from their homes.
South Sudan, the world's youngest nation, is so broke that the authorities say no official anniversary celebrations will be held.
But the streets of Juba were at least reported to be fairly quiet on Saturday.


Police will be deployed to a village in Mexico after an invitation to a girl's birthday party went viral and 1.2 million people said they would attend.

A video in which the girl's father says that "everyone is welcome" to the party featuring local bands, a meal and a horse race was posted on Facebook on a public setting.
He said the idea had been to invite neighbours and friends only.
But he has since confirmed he would not turn anyone away.
The video shows Crescencio Ibarra standing next to his daughter Rubi, wearing a tiara, and his wife Anaelda Garcia.
"Hello, how are you? We invite you this 26 of December to the 15th birthday party of our daughter, Rubi Ibarra Garcia," Mr Ibarra says, while his daughter smiles.
He then goes on to list the three bands that will play and announces that the winner of a horse race to be held as part of the event stands to win 10,000 pesos ($490; Â£390).
He ends by saying that "hereby everyone is cordially invited".
A girl's 15th birthday party is a big event in Mexico, as it is seen as the time when she comes of age.
Lavish parties with live bands are not unusual and girls traditionally wear puffy dresses, tiaras and make-up as they are "queen for the day".
It is not clear why this particular video went viral and was shared more than 800,000 times and prompted countless memes and imitations.
Mr Ibarra said in a TV interview he had no idea what had caught the public's imagination.
"We wanted to invite the people from the area, that's all," he said, before denying he had since uninvited all but personal acquaintances.
Mr Ibarra said that when he found out about the mass interest in their daughter's party and how some had poked fun at their rural ways he had been "sad" for two days but that the family had now got used to the idea and that the party would go ahead in a field outside the village of La Joya, in the state of San Luis Potosi.
Ms Garcia said: "Rubi is my daughter and she has always been our queen", before describing her favourite meme so far.
"It's the one about Donald Trump and [Mexican President} Enrique Pena Nieto coming to an agreement to allow undocumented Mexican migrants in the US to return to Mexico for Rubi's party."
Local lawmaker Roberto Alejandro Segovia Hernandez said police would be deployed to the village and the roads leading to it to ensure safety in case the crowds who said on Facebook they would attend really did descend on La Joya.
But even that announcement prompted fresh memes:
Rubi's older sister said Rubi was now "very excited" and looking forward to her party.


A British military healthcare worker has been flown back to the UK from Sierra Leone for Ebola monitoring.

The individual suffered a needle-stick injury while treating a patient in the West African country, which is among those affected by the Ebola outbreak.
The person has been admitted to the Royal Free Hospital in north London, Public Health England (PHE) said.
More than 22,000 people have been infected with Ebola and 8,795 have died in Sierra Leone, Guinea and Liberia.
The individual, who is being treated in isolation, does not have symptoms but is likely to have been exposed to the virus, the Royal Free said.
The patient arrived back in the UK on Saturday on board an RAF flight and will be monitored for the remainder of their 21-day incubation period.
Professor Paul Cosford, PHE's director for health protection, said: "Our thoughts are with this person, who has been courageous in helping those affected in West Africa, and in preventing the wider spread of Ebola.
"We have strict, well-tested protocols in place for this eventuality and we are confident that all appropriate actions have been taken to support the healthcare worker concerned and to protect the health of other people."
Needle-stick injuries involve a piercing of the skin by a sharp instrument or object, typically a needle.
Jonathan Ball, a professor of molecular virology at the University of Nottingham, said such injuries were "one of the most dangerous risks for infection" as the virus could be delivered directly into the bloodstream.
"Careful monitoring and Ebola virus testing will determine if the person has been exposed and infected," he added.
The Royal Free is home to a specialist unit for infectious diseases patients.
Two other Britons who contracted the virus - nurses Pauline Cafferkey and Will Pooley - have been successfully treated there, both of whom had worked in West Africa.
Ms Cafferkey was discharged last week. She said she was now looking forward to returning to "normal life" and had no current plans to return to West Africa.
She was treated with blood plasma from an Ebola survivor and an experimental treatment drug closely related to ZMapp, which Mr Pooley was treated with after he contracted Ebola.
Up until 5 January the Imported Fever Service (IFS) - which is a specialist diagnostic service for medical professionals managing travellers who have returned to the UK with fever - said it had received 258 calls regarding Ebola, and 148 tests had been carried out, with only two confirmed cases of the virus.


Eight England players are set to appear at the Indian Premier League when the 10th edition of the competition begins on Wednesday.

Ben Stokes became the IPL's most expensive foreign player when Rising Pune Supergiants bought him for £1.7m.
Bowler Tymal Mills, bought for £1.4m by Royal Challengers Bangalore, could face former international team-mate Chris Jordan in the opening match.
Jordan's Sunrisers Hyderabad play RCB in Deccan at 15:30 BST.
The Sunrisers, captained by Australia international David Warner, beat RCB in the final of the 2016 competition.
All-rounder Stokes could be in action on Thursday when his side play Mumbai Indians, who have wicketkeeper Jos Buttler in their ranks.
The competition features some of the best Twenty20 players in the world, including South Africa's AB de Villiers, Australia batsman Aaron Finch and India captain Virat Kohli.
England one-day captain Eoin Morgan joined Kings XI Punjab for £240,066, while limited-overs opening batsman Jason Roy was sold to Gujarat Lions and all-rounder Chris Woakes was bought by Kolkata Knight Riders for £504,140.
Sam Billings was also kept on by Delhi Daredevils during the first round of the auction.
Fast bowler Mills is available for the whole tournament as he is limited to playing T20 cricket because of back pain.
England's other players may not be available for the full competition because of international commitments, beginning when England host Ireland in one-day matches on 5 and 7 May.
The eight-team IPL format is similar to the proposed city-based Twenty20 tournament for English domestic cricket, which could be introduced in 2020.


Four men have been arrested after a fight involving football fans resulted in one man being injured.

Chairs were thrown outside Sinclair's Oyster Bar in Exchange Square in Manchester city centre.
Greater Manchester Police (GMP) tweeted the Polish football fans were held on suspicion of violent disorder.
A GMP spokesperson said the injured man was treated at the scene by paramedics for a head wound and the group of fans dispersed after officers arrived.
In a later tweet, the force said: "A fourth male was arrested after being found hiding in a restaurant near where the other three were detained."
The trouble flared before Manchester City's Champions League group match against Spanish side Sevilla at the Etihad Stadium, which kicked off at 19:45 BST.
Reports have suggested some of the people involved in the trouble were wearing the colours of Polish club Slask Wroclaw, whose fans have clashed with those of Sevilla recently.


A police motorcyclist is "lucky to be alive" after being rammed into a roundabout and almost run over, Essex police said.

Media playback is unsupported on your device
20 May 2015 Last updated at 19:05 BST
Martin Galbraith, 18, had just been escorted off the A13 at Grays for speeding when he drove his BMW into officer Paul Hills.
Police said Mr Hills was pushed 35 yards (32m) into the roundabout before he crashed.
Officers believe Galbraith then tried to run the officer over, but was blocked by another car.
Galbraith, of Boscombe Avenue, Grays, was eventually caught and jailed for six years for admitting attempted grievous bodily harm with intent, aggravated vehicle taking, driving without insurance and having no driving licence.


Aid agency Medecins Sans Frontieres is seeking to invoke a never-used body to investigate the US bombing of its hospital in the Afghan city of Kunduz.

MSF said it did not trust internal military inquiries into the bombing that killed at least 22 people.
The International Humanitarian Fact-Finding Commission (IHFFC) was set up in 1991 under the Geneva Conventions.
The US says last Saturday's bombing was a mistake. It came amid efforts to reverse a Taliban takeover of Kunduz.
Kunduz, a strategically significant city of about 300,000 inhabitants in north-west Afghanistan, was quiet for the first night in more than a week, reports said.
Security forces say they have spent the past few days mopping up Taliban remnants and sporadic fighting has been largely confined to the outskirts.
In depth:
MSF says the co-ordinates of the hospital were well-known and its bombing could not have been a mistake. The aid agency - winner of the 1999 Nobel Peace Prize - has said it is proceeding from the assumption that the attack was a war crime.
A number of inquiries have been ordered - by the US Department of Justice, the Pentagon, Nato and an American-Afghan team.
But MSF chief Joanne Liu told reporters in Geneva: "We cannot rely on internal military investigations by the US, Nato and Afghan forces."
She clarified that the IHFFC was "the only permanent body set up specifically to investigate violations on an international humanitarian law".
"We ask signatory states to activate the commission to establish the truth and to reassert the protected status of hospitals in conflicts," she added.
"If we let this go, we are basically giving a blank check to any countries at war," Ms Liu said.
According to the IHFFC provisions, an inquiry needs the specific endorsement of the parties to the conflict. Neither the US, nor Afghanistan is a signatory, and therefore they would have to issue separate declarations of consent to the investigation of the Kunduz bombing.
On Tuesday, Gen John Campbell, US commander of international forces in Afghanistan, said the attack had been requested by Afghan forces who were in communication with American special operations troops at the scene.
Those US forces in turn were in contact with the AC-130 gunship that fired on the hospital, he said.
"We would never intentionally target a protected medical facility," Gen Campbell told the Senate Armed Services Committee in Washington.
Saturday - Col Brian Tribus, spokesman for US Forces in Afghan
US forces conducted an airstrike in Kunduz city at 2:15am (local), Oct 3, against individuals threatening the force. The strike may have resulted in collateral damage to a nearby medical facility. This incident is under investigation.
Sunday - Pentagon press office
US forces conducted an airstrike in Kunduz city at 2:15am (local), Oct 3, against insurgents who were directly firing upon US service members advising and assisting Afghan Security Forces in the city of Kunduz. The strike was conducted in the vicinity of a Doctors Without Borders medical facility.
Monday - Gen John Campbell, US military chief in Afghanistan
We have now learned that on October 3, Afghan forces advised that they were taking fire from enemy positions and asked for air support from US forces. An airstrike was then called to eliminate the Taliban threat and several civilians were accidentally struck. This is different from the initial reports, which indicated that US forces were threatened and that the airstrike was called on their behalf.
Tuesday - Gen John Campbell to the Senate committee
On Saturday morning our forces provided close air support to Afghan forces at their request. To be clear the decision to provide aerial fires was a US decision, made within the US chain of command. A hospital was mistakenly struck. We would never intentionally target a protected medical facilityâ€¦ I assure you that the investigation will be thorough, objective and transparent.


A Russian man has been put into protective custody in hospital after he was attacked by a crowd of angry Mexicans in Cancun, authorities say.

Police rescued Aleksei Makeev, 42, on Friday night after the crowd stormed his apartment in the Caribbean resort.
The man had allegedly posted disparaging and insulting remarks about local people in videos on social media.
He was accused of fatally stabbing someone during the affray, the authorities said.
A crowd of locals tried to confront Mr Makeev over his comments, and managed to gain entry into his apartment after the encounter turned violent.
According to local official Guillermo Brahms, a young man who was injured later died in hospital.
Mr Brahms said police managed to rescue Mr Makeev and take him to hospital for treatment. Although he was bloodied in the attack, he is reported to be in a stable condition.
Footage of the attack circulated in Mexican media on Saturday, with the attackers heard shouting "You're going to die" and "I'm going to cut your head off".
Police say frequent complaints had been made about Mr Makeev's behaviour and requests had been made to deport him.
Some of the videos he had posted were against a backdrop of swastikas, officials said.


One of the UK's oldest photography studios is set to display part of its "vast" historic archive to the public for the first time.

Derby's WW Winter opened in 1867 in the same Midland Street building it occupies today.
Large glass plate negatives from the late 19th to the early 20th Century, which go on show next week, offer rare glimpses of Derbyshire, including German prisoners of war held there during World War One.
The prisoners - mostly officers - were held from 1915 to 1918 at Donington Hall on the Leicestershire border, where they formed sports teams.
There will be other pictures of Derbyshire in wartime on display, including these shots of British soldiers at Derbyshire barracks.
WW Winter's studio was photographer by Royal Appointment to King Edward VII and there are a number of negatives of the monarch in the archive.
The studio has become the first business in the East Midlands to receive a Heritage Lottery grant, after the National Lottery recently allowed private firms to apply.
It has been granted Â£51,800 to employ an archivist to start preserving and cataloguing its archive of glass negatives.
"We know there is a vast collection of photographs of Derby residents and city scenes but within our day-to-day operations we do not have the resources to work with the collection and thus, until now, it has sat dusty in the cellar unseen," said photographer Louisa Fuller.
She said the funding is an "exciting opportunity" to digitise the archive and make it publicly accessible.
Pictures of Derby's cricket pavilion and a team shot of Derby County players from 1888 are also included in the collection.
The photographs are on display from September 11 to 13.


An investigation has been launched after a fire on a trading estate in Worcester.

The fire, which broke out at about 20:42 BST on Tuesday at the Blackpole Trading Estate, destroyed about 60 scrap vehicles, tyres and heavy machinery, Hereford and Worcester Fire and Rescue said.
Six engines tackled the blaze which was brought under control at 22:55.
The service said it was investigating the cause of the fire.


An inquest into the IRA killing of 10 Protestant workmen in County Armagh has been told that a key suspect has been linked to almost 50 murders.

The Belfast Coroners' Court inquest into the murders more than 40 years ago was hearing from a barrister for some of the victims' families on Wednesday.
The 10 men were ordered out of a bus and shot in January 1976 in what became known as the Kingsmills massacre.
No-one has ever been convicted in connection with the killings.
Speaking in court, the families' barrister referred to a Police Service of Northern Ireland review of the case that was conducted after a report by its Historical Enquiries Team in 2011.
The barrister said the police review linked a "prime individual" to 46 murders that happened between 1974 to 1976.
The killings included 22 civilians, one of whom was a seven-year-old boy.
The other murders involved 21 soldiers, two police officers, and a paramilitary activist.
The inquiry into the massacre is also seeking clarity on the status of so-called 'on-the-run' letters after it was claimed that a number of suspects in the massacre received the controversial correspondence.
The controversial letters were issued by the government and assured the recipients that they were not being sought by police.
During the cross-examination of a police intelligence officer on Wednesday, the barrister asked if forensic evidence that is not new "dies a death" because of the letters.
The police witness said he did not know and therefore could not answer the question.
The coroner said he was also not clear on the status of the letters and the hearing would keep "an open mind" on the question.
He said it may be that some other witness will be required to provide an answer.
The inquest into the killings has resumed this week after being adjourned last year due to a police investigation.
It also heard on Wednesday about a secret intelligence document that recorded details of a self-confessed member of the IRA providing a list of 11 suspects.
The hearing was also informed of police intelligence that linked a "crack unit" of the IRA in Whitecross in County Armagh with the massacre.


A 17-year-old girl has been left "very shaken" after being sexually assaulted on a train by a man wearing a Christmas jumper.

The incident happened on the 23:09 service from Dunblane to Edinburgh on 16 December shortly after the train left Larbert railway station.
A man who was sitting in the seat next to the girl placed his hand on her legs twice.
She was able to alert a conductor who helped her to move seats.
The man was described as white, about 5ft 11in tall, in his late 20s, with strawberry blonde hair.
He was wearing a Christmas jumper and jeans at the time.
PC Andrew McAinsh, said: "Everyone should be able to travel on the railway network without experiencing unwanted sexual behaviour.
"I would like to commend the victim for reporting what happened to her.
"She was very shaken by the incident and an investigation is under way to identify the offender."


Police in the Greek capital Athens have stopped the far-right Golden Dawn party from handing out free food only to Greeks on the city's main square.

Riot police used tear gas to prevent activists distributing food from a lorry on Syntagma Square, where the country's parliament is located.
Athens Mayor Giorgos Kaminis says a Golden Dawn MP later tried to assault him for banning the gathering.
Golden Dawn, once a fringe movement, is now Greece's fifth-biggest party.
It was staging the handout to celebrate Greek Orthodox Easter, which falls this weekend. At past events, the anti-immigration party asked recipients to show ID cards proving they were Greeks.
Golden Dawn reportedly managed to hand out some food before police moved in, and it later continued the distribution elsewhere in the city.
Mr Kaminis said no party could use the square for such purposes and vowed to prevent "thuggery".
The mayor told the BBC that a Golden Dawn MP tried to attack him at a charity centre he was attending later in the day.
Bodyguards managed to restrain MP Giorgos Germenis, he said, although a 12-year-old girl was injured in the process.
Mr Kaminis says he plans to sue the MP over the incident, which was reportedly caught on camera.
Speaking to the BBC, the mayor called members of Golden Dawn "criminals".
The party, whose neo-Nazi ideology has been condemned by human rights groups, has soared in popularity during the financial crisis.
Greek authorities have been accused in the past of failing to take action against hate crime and attacks on immigrants.
Mr Kaminis said Thursday's police action was a "victory for the democratic state".
"Thuggery will not prevail in this city as long as I am mayor," he was quoted as saying by the Greek newspaper Kathimerini.


The UK's Brexit minister David Davis has hailed his latest talks with devolved ministers but Holyrood's Mike Russell has called for greater clarity on the "strategic objectives".

The views were expressed following a meeting of the EU Negotiation Joint Ministerial Committee in London.
Mr Davis said the UK government would keep Scotland, Wales and Northern Ireland up-to-date about negotiations.
However, Mr Russell said transparency about UK government plans was needed.
Mr Davis said he wanted to hold a monthly meeting to share analysis as part of a "two-way information flow" with each of the three nations.
He believed that would allow the devolved administrations to voice their views as the Westminster government prepares talks with Brussels.
Mr Davis said: "Today's meeting was an important step in bringing the devolved administrations together with the UK government to discuss how we can work together to get the best deal for the whole of the UK.
"Naturally, there are different standpoints around the table, but the meeting was constructive and amicable. We will meet regularly and share our latest thinking as the UK shapes its negotiating strategy.
"We will work positively with the Scottish government, the Welsh government and the Northern Ireland Executive as we implement the decision of the people of the UK to leave the EU."
Mr Russell said it was "good" that the process of involving the Scottish government was under way.
But he added: "More than four months after the referendum the UK government has still not made its strategic intentions clear.
"There was a discussion over EU market access but we do not know whether UK ministers want to remain inside the single market or the customs union. This will remain a considerable problem as we continue to promote the interests of Scotland.
"The UK Government must provide greater clarity and transparency on its intentions."
He said he made it "absolutely clear" that membership of the single market "is essential for the economic prosperity of Scotland".
The UK government hopes the High Court judgment on how Article 50 will be triggered will be overruled on appeal to the Supreme Court next month.
However, the Scottish government will seek to oppose the UK government in the Supreme Court during the appeal.
The intention is for Lord Advocate James Wolffe, Scotland's most senior law officer, to apply to be heard in the case.


The battle to become the official campaign to quit the EU has finally been settled by the Electoral Commission.

Its decision means Vote Leave gets increased spending limits of Â£7m during the campaign period, campaign broadcasts and a free mail-out to households.
But why was Vote Leave, not the rival Grassroots Out organisation, chosen?
Lead EU campaigns named
Live: Reaction to the EU campaigns announcement
Speaking after the announcement, Grassroots Out's Peter Bone joked that his group's distinctive green ties might have swung the decision against them.
In fact, the criteria were rather more technical.
Electoral Commission chief executive Claire Bassett said both had submitted "high quality" applications, which had been analysed "in some detail".
In the end, she said, it came down to which group had the greater "depth of representation" of EU exit campaigners.
The final decision was taken at an Electoral Commission board meeting this morning.
Both organisations - as well as the Trade Unionist and Socialist Coalition (TUSC) - had submitted applications setting out their case.
The commission's scorecard reveals Vote Leave scored 49 to Grassroots Out's 45. It rated higher in the categories of "support for application", "representing other campaigners" and "organisational capacity".
The commission said both groups had demonstrated support from a wide range of organisations - but Vote Leave had "better demonstrated the depth of representation in their support from those campaigning, including at a regional and local level".
It also had "well-developed plans... for how they would support other campaigning organisations", the commission said.
The left-wing TUSC's application was rejected as it "did not demonstrate that it adequately represented other campaigners".
Asked about the possibility of a judicial review bid by the Grassroots Out-supporting Leave.EU campaign, Ms Bassett said the commission's decision had been reached "transparently, openly and robustly" and she was confident it would withstand a challenge.


A petition urging shops to stay closed on Boxing Day to give staff a break has been backed by more than 100,000.

Retail workers are "being bled dry" by "greedy employers", supporters wrote on the petition's web page.
Ian Lapworth, a baker from Kettering, started the campaign a month ago, calling for a return to a less commercialised holiday season.
"Forget making money for one day, let's concentrate on making more memories with the ones we love," he said.
Called "Stop Shops opening on Boxing Day", the petition argues retail staff should get a longer break over the Christmas period. It will be delivered to Prime Minister Theresa May if it reaches 150,000 signatories.
"Whilst not everyone may see Christmas as a religious holiday, it should be respected as such, and retail workers (who work so hard on the run up to the big day) given some decent family time to relax and enjoy the festivities like everyone else," the petition says.
Thirty or 40 years ago, shops stayed closed for longer periods during the holiday season. The trend in recent years is for retailers to extend their sales periods, opening early on Boxing Day to compete for customers requiring staff to return to work, sometimes after only one day off.
"I've worked in retail nearly 10 years. We never used to open and we shouldn't," wrote one of the petition's signatories. She said she would rather spend more time at home with her son, but her contract obliged her to work.
"I'm not a doctor where I would be saving someone's life. I'm a sales consultant. I sell clothing and other household items to people that quite frankly don't have a life on Boxing Day."
Another signatory agreed: "It's disgusting how shops still insist on opening on Boxing Day, they bleed retail workers dry in the run up to Christmas."
Others blamed "greed" on the part of employers for the long hours.
In centuries gone by, once Christmas Day festivities were over, the wealthy would parcel up gifts for their servants and tradesmen. The first working day after 25 December became a bank holiday, with businesses and shops closed to mark the custom, in the UK and Commonwealth countries.
Nowadays it's many people's favourite day to return unwanted Christmas gifts for a refund. Retailers hoping to draw out a bit of extra spending, began offering big discounts and now Boxing Day sales tend to merge seamlessly into what were previously January sales, helping companies off-load unsold seasonal merchandise.
One supporter of the petition said his work schedule meant he did not have time to enjoy Christmas.
"I am a retail manager and I haven't spent time with family for Christmas since I was 15.
"I have to go to bed early on Christmas Eve due to being exhausted from setting up sales for Boxing Day and I have to go to bed early Christmas Day and avoid spending time with family or having any celebratory drinks, as I have to then work all the way through New Year's as well."
While some retailers may be tempted to respond positively to the petition, they're unlikely to break ranks with the rest of the High Street, according to Patrick O'Brien, analyst at Verdict Retail.
"Some retailers might view the benefits of closure in staff morale, giving them a break. But it's still quite an important day in the retail calendar.
"It wouldn't hurt them if all of them did it, but unfortunately if some [close] and some don't, the ones that don't would be financially affected."
The British Retail Consortium said companies would continue to respond to demand from shoppers, deciding opening hours "based on customers' needs and preferences".
"Boxing Day is a popular time to take advantage of the post-Christmas sales and retailers will respond accordingly to cater for this customer demand," a BRC spokesperson said.
The petition coincides with the launch of Sainsbury's Christmas advert which plays to a similar theme, of harassed workers, struggling to find time to enjoy the simple things over the festive period. In it an overworked father battles the queues in the shops, long hours at his workplace - a toy factory -  and rail delays that many commuters will recognise.
It also comes at a time when retailers are reconsidering their Christmas sales strategies. In previous years much touted Black Friday sales saw vast crowds and chaos in some stores. The day was more muted last year, as companies toned down their sales pitches. But retailers still want to make the most out of shoppers' enthusiasm for a bargain.
To that end Amazon has announced it is running two weeks' worth of pre-Christmas promotions in the run up to "Black Friday" - the day after the American Thanksgiving holiday. In the US, it is the day the Christmas shopping season starts in earnest and retailers vie for the most eye-catching promotions.


Long after Oliver Thompson-Smith's physical injuries had healed, the young man was still suffering.

As a 19-year-old student on a night out in Chester, he had been brutally stabbed and mugged, near his home.
"I couldn't let it go in my head. It was always there," he says. "It started creeping into my nightmares."
He bottled up the fear and trauma for four years, before a suicide attempt prompted him to seek help, perhaps surprisingly, from his manager at work.
But Oliver is by no means typical. Around half of us would not be happy to speak up at work if we had a mental health problem, according to a survey conducted by Comres for BBC Radio 5 live.
The survey asked 1,104 British adults in full-time employment about their attitudes to mental health. And 49% said they would be unlikely to tell their boss about problems such as anxiety, depression or bipolar disorder.
Only 35% said they'd be happy to tell colleagues.
Despite his dreadful experience, Oliver is one of the lucky ones. His employer at the time was the construction firm, Laing O'Rourke; he was working on the Crossrail project in London.
His manager was one of the first people he turned to, and because the company has a positive approach to mental health in the workforce, they were able to have a very open and frank conversation.
"He helped point me in the right direction in terms of who to speak to at work, a confidential advice line we have at Laing O'Rourke, who helped me start therapy and has really helped me since then in terms of getting my career on track and do what I can to really help myself," he says.
But according to Sue Baker, director of mental health charity, Time to Change, turning to your boss is not always the best course of action.
"We wouldn't encourage people to routinely disclose," she says. "Because obviously there's really poor practice still.
"It can result in people being passed over for promotion, not being offered opportunities to develop themselves, and to outright discriminatory comments."
She advises people to speak up only if it's clear your employer is supportive of mental health programmes.
But there are, she says, now more than 500 employers taking positive action, including signing up to the Time To Change pledge, which commits them to address the taboos around mental health.
Ms Baker says about one in six people suffer some kind of mental health problem making it an issue for the entire workforce.
"There are millions of people who are less productive because they are not getting help," she says.
"It costs industry more to ignore mental health and shove it under the carpet than to deal with it."
Pizza Hut Restaurants is one of the firms that has signed up to the charity's pledge.
"We have 8,000 people from age 16, to people who've worked for us for 30 years," says the firm's head of communications Gareth Hopley.
"A lot of our managers are 21-year-olds who you're asking to run multimillion pound restaurants.
"The aim is to try to create a culture that says it's ok to put your hand up and say I'm struggling," he says.
So when Pizza Hut Restaurants launched a turnaround programme a couple of years ago, a conscious effort was made to focus on improving staff well-being alongside revamping menus and refurbishing restaurants.
The firm has introduced an internal social network called No Shame which encourages discussion of embarrassing topics including mental health, to lessen the stigma around it. Around half of the company's staff use it, says Mr Hopley.
There's also a 24-hour helpline for staff to get advice on anything from anxiety and addictions, to relationships, dieting and fitness.
Mr Hopley believes the business as a whole is benefiting.
"As a business, we want to have a content, happy, engaged workforce, that feels we support them, because then you have a more dedicated, committed team that wants to give a great service to the customers."
BBC Radio 5 live is currently running a year-long State of Mind season, which takes an in-depth look at our mental health.


An academy company that runs seven schools in Oxfordshire has been put into financial special measures after running up a deficit of £879,000.

The government has issued the The Dominic Barberi Multi Academy Company a financial notice to improve because of its "weak financial management".
The company is based at St Gregory The Great Catholic School in Cowley.
The government will now monitor all the company's financial transactions until the notice is lifted.
The company also runs St Thomas More in Kidlington, St John Fisher in Littlemore, Our Lady's in Cowley, St Joseph's in Thame, St Joseph's in Carterton, and Our Lady of Lourdes in Witney.
Its annual report puts the deficit down to "high expenditure that went unchecked against a background of weak financial controls and lack of transparency around the company's finances".
It continues: "The company's board has acted to strengthen controls and improve visibility of the company's trading and cash performance: in addition the board has imposed restrictions on expenditure."
Melinda Tilley, cabinet member for education at Oxfordshire County Council, called the situation "very worrying".
She added: "I'm worried about the other six schools that they also support.... I think they need a very good finance person on the school governing body.
"I know that probably we'll end up finding school places for all the children if they walk away, and certainly the transport for the schools... if it does go wrong."
The BBC has asked the Dominic Barberi Multi Academy for comment.


A couple who lost their newborn baby have raised more than £12,000 towards buying an area of woodland in his name.

Jo Meeke and Matt Gurney's son Puck died in hospital following complications in labour.
They have set up an appeal to create an outdoor space for other grieving families and hospital staff.
Ms Meeke, from Bosham in West Sussex, said she hoped the woodland would help people on the "long journey" of coping with the death of a child.
She had an "uncomplicated dream pregnancy" but after complications in labour, Puck was born via emergency Caesarean section on 15 March.
He was transferred from St Richard's Hospital in Chichester to Southampton General Hospital's neonatal ward, where he died the following day.
When it became clear he would not survive, the couple had 30 minutes to say goodbye.
Ms Meeke said the time together had been "a special moment that will live with us forever".
"The hardest thing we're having to deal with now is the immediate raw grief of looking at photos of our son, knowing we're not going to hold that little boy," she said.
"But it's all the other things we had planned for our family moving on - suddenly those things are not going to happen."
The couple has set up the Puck's Promise appeal and aim to crowd-fund £65,000 to buy the woodland.
Mr Gurney said he hoped it would bring "something positive" out of their experience.
"I'd primarily like families who have lost children in some way to be able to use it, for a walk or overnight camp, to be with other people who have been though the same thing."


St Mirren have signed former Hibernian striker Ross Caldwell on a one-year contract, with the option of a further year.

The 20-year-old has impressed Buddies manager Tommy Craig during a trial in pre-season.
Caldwell made his debut for Hibs in 2011 and made 19 appearances in 2012/13, scoring two goals.
"We hope that we develop him into the player that we believe he can be," said manager Craig.
Caldwell fell out of favour under boss Terry Butcher last term and was loaned to Scottish Championship side Alloa, for whom he scored twice.
"I am delighted to have joined St Mirren," the front-man said.
"Having been at the club now for a couple of weeks I have thoroughly enjoyed every minute and already feel part of the set up.
"I now want to repay the faith shown in me by Tommy, Gary [Teale] and Jim [Goodwin] in the season ahead."


Politicians have called for an inquiry into the sale of Nama's Northern Ireland loan portfolio following revelations in a BBC Spotlight programme.

Businessman, Frank Cushnahan, who has been at the centre of the controversy, claimed in a covert recording made last year, that he was due to be paid a fixer fee in relation to the sale.
Mr Cushnahan was an adviser to Nama.
He has consistently denied he was due to receive money.
Nama NI deal jargon buster
Timeline of Nama's NI property deal
Sinn Féin President Gerry Adams has said there should be a Commission of Investigation held in the Republic of Ireland while Alliance Deputy Leader Naomi Long has called for an independent investigation.
Nama is the Republic of Ireland's "bad bank".
It sold its entire Northern Ireland loan portfolio to the Cerberus investment fund in 2014.
Mr Cushnahan, a former banker, was appointed to Nama's Northern Ireland advisory committee by the DUP.
Unknown to Nama he began talking to a US investment fund, Pimco, who were interested in buying the entire Northern Ireland portfolio.
Prior to leaving his post at Nama, Mr Cushnahan attended meetings with Pimco as it prepared to mount a bid.
He was due to be paid £5m if the bid succeeded - but it collapsed when Nama learned of Mr Cushnahan's role.
Another company called Cerberus then bought the loan portfolio for more than £1bn.
Nama had received assurances that no one connected with Nama (which would include Mr Cushnahan) was to benefit from that deal.
However, in a covert recording, Mr Cushnahan discusses work he did with a Belfast solicitor Ian Coulter.
He said: "You know when I was working on that Cerberus thing to get that thing out, he worked with me to get that. And basically all the work was done by me and him."
He goes on to say his role was deliberately hidden because of Nama's objections.
Cerberus has previously stated that it has "never employed, paid or sought advice from Frank Cushnahan in relation to our purchase of the Project Eagle portfolio or any other activity."
Nama said it had dealt with the issue "very extensively over the past 12 months" and had nothing further to add at this time.


Twenty Yemeni soldiers have been killed in an attack on a military checkpoint in eastern Yemen, reports say.

Yemen's state-run Saba news agency reports the attack took place in the province of Hadramawt.
Security sources earlier said eight had died and six were wounded in an attack that one source attributed to al-Qaeda in the Arabian Peninsula (AQAP).
The Yemeni military has been tackling a powerful al-Qaeda insurgency in the province in recent years.
Hadramawt is a centre of oil production and seen as a stronghold for AQAP, which has been waging a campaign against the Western-backed government.
"Twenty soldiers were killed in the armed attack on an army checkpoint" near Reida, about 135km (85 miles) east of the provincial capital Mukalla, Saba reported.
One source told the AFP news agency that the attack was carried out by gunmen in several vehicles.
Last year, the army managed to drive al-Qaeda out of towns it had taken over in southern Yemen amidst the chaos triggered by a mass uprising against the veteran President Ali Abdullah Saleh in 2012.
But this year, its members appear to have regrouped, carrying out a wave of attacks on security targets, says the BBC's Arab affairs editor Sebastian Usher.
In a gruesome warning, the group recently executed one of its own and displayed his body, claiming he had been a spy helping US drones to hit al-Qaeda leaders, he adds.


Twelfth of July parades have taken place in 18 locations across Northern Ireland, as the Orange Order staged the biggest day in its marching calendar.

Tens of thousands of people were involved in the parades that mark the anniversary of the Battle of the Boyne.
The Grand Orange Lodge of Ireland's grand master described Wednesday's Twelfth as the "biggest in a generation".
Edward Stevenson said "unprecedented numbers of people" had attended.
Twelfth of July demonstrations are billed as a celebration of Protestant religion, heritage and culture, and marchers were commemorating the Boyne battle's 327th anniversary.
William III - the Dutch-born Protestant better known as William of Orange or King Billy - defeated the Catholic King James II in County Meath in July 1690.
The Police Service of Northern Ireland (PSNI) said Wednesday had been the "most peaceful" Twelfth "for some years".
Three people were arrested on Wednesday, as well as six people on Tuesday night for disorder associated with bonfires.
But the PSNI's Assistant Chief Constable Alan Todd said: "From a policing point of view, events today have pretty much reflected the weather - it's been a good day."
He added that a small number of Eleventh Night bonfires on Tuesday had been "sectarian and racist" and that police are investigating.
Mr Stevenson said there had been a "family-friendly and carnival atmosphere" to the parades on Wednesday.
"The wonderful weather exceeded our expectations; as did the tens of thousands of our members, band personnel and supporters, taking part in or lining the routes of 18 venues across the province," he said.
"Such a phenomenal spectacle bears testament to the continuing relevance and wide appeal of Orangeism."
While the vast majority of Twelfth parades typically pass without incident, a small number have proved contentious in the past, with some nationalists objecting to public roads being closed to facilitate the marchers.
Tensions around contentious parades have eased, with residents and the Orange Order reaching agreements, and the mood on the streets in many areas this year appears to have been more relaxed.
Orange Order grand secretary Mervyn Gibson said there was "less tension" this year.
"We took a deliberate decision last year not to issue statements about parades so that would not increase tensions," he said.
"I believe that paid off and we have built on that this year.
"There are still issues around parades that have to be dealt with, but we don't want to ruin the Twelfth of July for ourselves or anyone else."
The Ardoyne feeder parade in north Belfast - a flashpoint in previous years - took place on Wednesday morning.
The parade passed peacefully and Sinn FÃ©in MLA Gerry Kelly said there was a "huge change of atmosphere".
"More and more people from Ardoyne and from Twaddell and from residents groups should meet each other and that has always been going on in north Belfast - it is a good day," he added.
The main Orange Order parade passed by St Patrick's Catholic Church in Belfast - another area in which tensions have risen in the previous year - without incident.
Bands abided by the ruling that only a single drum-beat should be played while passing the church.
There was no protest and a more low-key police presence than in previous years.
The Orange Order was formed near Loughgall in County Armagh in 1795, when its founding members pledged their loyalty to the royal family and swore to defend the Protestant faith.
On 12 July, marching bands from Orange lodges all over Northern Ireland parade through villages, towns and cities before listening to speeches and prayers by senior Orangemen.
Traditionally, the biggest Twelfth gathering is in County Armagh, but a major demonstration was held in each of the six counties in Northern Ireland.
Many smaller towns and villages take turns hosting their neighbouring districts, but Belfast and Ballymena in County Antrim stage a Twelfth parade every year.
This year's 18 hosts were:
The Orange Order said a "large Scottish contingent" travelled to Belfast to take part in the commemorations.
This year also marks the 500th anniversary of the Protestant reformation.
As a result, some lodge members carried new banners depicting the German theologian Martin Luther.


Venezuelan security forces have surrounded the public prosecutor's office in Caracas in what the chief prosecutor has called a "siege".

It came a day after the embattled government inaugurated a new legislative body, the 545-member constituent assembly.
Chief prosecutor Luisa Ortega had asked a local court to halt the inauguration.
She cited allegations that the government had misrepresented the results of the vote that created it.
"I reject the siege of the headquarters of the public prosecutor's office," Ms Ortega, a leading critic of President Nicolas Maduro, wrote on Twitter on Saturday.
"I denounce this arbitrary act before the national and international community."
President Maduro says the constituent assembly - which is due to begin work on Saturday - is needed to bring peace after months of crisis sparked by the country's economic implosion.
But the opposition says the new body, which has the ability to rewrite the constitution, is a way for the president to cling to power.
On Friday in Caracas, police used tear gas against opposition protesters who tried to reach parliament.
Several people were injured as security forces tried to disperse a few hundred demonstrators, reports say.
In other parts of the city, thousands of government supporters gathered to cheer and wave flags as the new members took office. Some carried pictures of late leader Hugo ChÃ¡vez and the independence hero SimÃ³n Bolivar.
Among those sitting for the first time in the 545-member assembly are Mr Maduro's wife and son.
A close ally of Mr Maduro, former foreign minister Delcy Rodriguez, was elected president.
Her opening speech attacked the opposition as "fascist" and warned the international community against interfering.


Rafael Nadal saw off the threat of Novak Djokovic for another year to win his ninth French Open title and a record fifth in succession.

The Spaniard, 28, coped better in hot conditions as he won 3-6 7-5 6-2 6-4 in three hours and 31 minutes.
Nadal is the first man ever to win a major title nine times, taking his Grand Slam total to 14.
The victory also means he will remain world number one ahead of Djokovic.
"In matches like this every moment is crucial. Playing against Novak is always a big challenge, I had lost against him the last four times," Nadal said on court.
"I feel sorry for him today, he deserves to win this tournament."
It is the third year in a row that Nadal has ended Djokovic's hopes of winning the one Grand Slam title he lacks, with the Serb in particular struggling on a stifling Parisian afternoon and ending with a double fault on match point.
"Congratulations to Rafa and his team, it is incredible to win this tournament nine times," Djokovic said.
"It was an emotional day. I have tried with all my power, my strength, my capacities but Rafa was the strongest on court."
Nadal extended his incredible run at Roland Garros to 66 wins and just one defeat in the last 10 years.
That record looked under threat when he dropped the first set as his usually fearsome forehand let him down, five errors handing Djokovic the initiative.
"Never mind the back problems he had in Australia and the error-strewn performances of the early clay court season - Rafael Nadal once again timed his run to perfection at Roland Garros. It was a brutal scrap at times, but Nadal looked like he would be very hard to beat after wrestling the momentum away from Djokovic midway through the second set.
"The Spaniard is just 67 days older than Roger Federer was when he won his 14th Grand Slam title: his claim last week that a generation is walking away now looks exceedingly premature."
Both men were having to work hard in temperatures of around 27C, and Djokovic was the first to ask for iced towels to wrap around his neck at the changeovers.
Nadal finally made his move when he broke for 4-2, only to lose his advantage straight away as the nervous errors returned in the following game.
Djokovic had won their last four matches but taking on Nadal in a five-set contest on Court Philippe Chatrier is a very different kind of test.
The 27-year-old Serb faltered badly with a tie-break in sight, offering up a double fault and a forehand error before Nadal smacked a forehand winner to level the score.
It was a huge blow to Djokovic's hopes and he faded further in the third set.
After dumping a straightforward volley in the net to lose serve in game two, the second seed took some tablets at a changeover in an attempt to improve his condition.
Nadal scented victory once again, breaking twice on his way to the set and leaving Djokovic to stare in disbelief at coach Boris Becker in the stands after one error.
Another poor volley and a wild backhand into the tramlines saw Djokovic fall 4-2 down in the fourth, but Nadal was now having his own issues, bending over apparently in some discomfort and badly mistiming a smash to give the break straight back.
With cloud cover giving Djokovic some respite from the sun, he was showing signs of launching a renewed assault only to falter with his opponent under pressure.
A terrific backhand pass helped Nadal to match point and Djokovic, disrupted by a call from the crowd, fired his second serve long to leave the Spaniard on his knees in his familiar celebratory pose.


A former Newport primary school head teacher allowed staff to manipulate national test results, a General Teaching Council for Wales panel heard.

Samantha Yeoman, the former head at Rogerstone Primary School, is accused of allowing teachers to see exam papers before the tests and giving pupils extra time to complete them.
Ms Yeoman resigned from her post last year, the conduct hearing was told.
Her counsel said she was not leading the tests at the time.
Gwylim Roberts-Harry told the hearing on Monday his client only became aware of "certain elements" after the tests.
The panel heard she allowed staff to manipulate the 2013 National Reading and Numeracy Test results, so pupils would achieve better grades.
The school's deputy head teacher, Wayne Millard, told the hearing Miss Yeoman returned from a conference, where she said the majority of teachers indicated they had been shown the test papers.
He said Miss Yeoman "became angry" when she found out her teachers had not been shown the tests. He said a timetable was then drawn up for them to view them.
The panel was also told of claims pupils were called back to change wrong answers on their test papers.
A complaint was also made by a parent who claimed the way tables were arranged in her daughter's class meant she could see the test answers on her teacher's desk.
Miss Yeoman is also alleged to have applied undue pressure on staff by agreeing unrealistic standards, and creating a threatening and intimidating work environment for staff.
She denies unacceptable professional conduct and did not attend the hearing.
Evidence is expected to continue for the rest of the week.


Grandparents should be given the right to request unpaid leave as they are so involved with childcare, the TUC says.

It has called for an extension of their right to ask for time off to look after grandchildren, which currently only applies in emergencies.
The TUC estimates that seven million grandparents provide regular childcare for youngsters aged under 16.
The government said it was extending the right to request flexible working to all employees from April 2014.
A separate report suggests many of these grandparents will be better off than the next generation.
People born in the 1960s and 1970s will rely on inheritance in order to be better off in retirement than their predecessors, according to the Institute for Fiscal Studies (IFS).
The most common reason for grandparents to take on childcare duties, according to the TUC, is to allow the child's parents to go to work.
It said that its survey suggested that working grandparents were more likely to help look after grandchildren than retired grandparents.
Consequently it wants to see a clearer right to ask for unpaid leave, such as one day a fortnight, rather than just being able to ask an employer for the occasional emergency day off.
"The informal childcare that millions of grandparents regularly provide is one of the most important and unheralded forms of care in Britain today," said TUC general secretary Frances O'Grady.
"The childcare provided by grandparents allows mums and dads to work, saves them money on nursery and childminder fees, and creates a special bond across different generations in a family.
"Many businesses have yet to keep up with this trend and thousands of grandparents who want to look after their grandkids are prevented from doing so. It's important that public policy catches up with the needs of working grandparents and their families."
A spokeswoman for the Department for Business said: "Making flexible working available to all will not just benefit grandparents but allow the wider family to help out with child caring responsibilities. It will give all employees the opportunity to better balance work with their personal life."
The TUC's call comes on the same day as the IFS report suggests that many of today's parents are relying on inheritance to continue the trend of being better off than their predecessors.
It said that, when compared with those born a decade earlier, pay was no higher and their savings no greater for those born in the 1960s and 1970s, when inflation was taken into account.
They were also less likely to own a home, would have lower pension wealth and were likely to see a proportionately lower state pension compared to earnings.
"Since World War Two, successive cohorts have enjoyed higher incomes and living standards than their parents. Yet the incomes and wealth of those born in the 1960s and 1970s look no higher than [those] who came before them," said Andrew Hood, who wrote the report.
As a result, he said, those born in the 1960s and 1970s would see this topped up by inheritance, but this was unequally distributed and tended to benefit those who were already wealthy.


Saracens director of rugby Mark McCall says how his squad react to their heavy defeat by Wasps will be crucial as the club are in a "challenging period".

The Premiership leaders conceded three tries in the first eight minutes and eight in total as they were beaten 64-23 at Allianz Park on Sunday.
"We didn't see it coming and it's hard to put into words what happened out there," he told BBC Radio London.
"This is a very big setback. The important thing is what happens next."
Saracens conceded the most points at home in their history as they suffered just their second defeat of the season.
"It went wrong right from the beginning and we were given a real lesson by Wasps with and without the ball," McCall added.
"When you concede 60 points, there is clearly an issue. Every time they got down our end they came away with a try.
"We have shown some real energy and resilience in the last couple of performances but that, as a collective, wasn't the case against Wasps."
Saracens had seven players on Six Nations duty with England in Italy, but McCall declined to blame international commitments for their defeat.
"This squad we played with had a great result at Exeter last week, so we are not going to use that as an excuse," the 48-year-old said.
"This is a challenging period, no question about that.
"Next week we play against a team on form in Gloucester. It is important we put some of the really bad things right."


The family and friends of a missing man from Fife have taken part in a march to try to jog people's memories about the night he disappeared.

Allan Bryant, 24, was last seen leaving the Styx nightclub in Glenrothes on 3 November 2013.
Police carried out extensive searches of the area, using specialist teams of divers and dogs, but there have been no further confirmed sightings of him.
His family hope the march will remind people that he is still missing.
About 100 people walked through the town in a bid to prompt members of the public to come forward with information.
Police Scotland welcomed the march.
Ch Insp Nicola Shepherd said: "The search and inquiry into Allan's disappearance continues and we are totally committed to finding Allan.
"Throughout our investigation we have been supported and assisted by many of Allan's family and friends who have turned out in large numbers to volunteer to help search for Allan.
"Their assistance and support has been invaluable to the officers dedicated to this inquiry.  The support from the wider community in Glenrothes has been remarkable and is testament to the community spirit and their willingness to help.
She added: "We continue to support his family and seek assistance from the public to think back to what they were doing on the night of Saturday 2nd November and into Sunday 3rd November 2013.  Were you in the area?  Did you see Allan?
"Allan's family are desperate for news about him and I would appeal to anyone who has information, no matter how insignificant they may feel it is to contact us."


The comments section of Britney Spears' Instagram account has been used by cyber-thieves to co-ordinate attacks.

Security firm Eset found the gang controlled its malware, called Turla, by posting comments about images in the singer's gallery.
The comments looked like spam but once transformed by code in the virus, directed victims to other sites.
Several other compromised websites were also being used to track victims and spread the malware.
Turla has been active since 2014 and sought to catch out government workers, diplomats and other officials, said Eset researcher Jean-Ian Boutin. It is believed to be run by a hacker group working for the Russian state.
Most often, he said, Turla's handlers compromised websites that targets would be likely to visit.
One compromised server asked visitors to install a booby-trapped extension for the Firefox web browser.
Digital detective work by Mr Boutin revealed that the command and control (C&C) channel set up between the creators of the extension and victims' machines was on the singer's Instagram page.
The malicious extension searched for comments that, when digitally transformed, matched a specific value. These were then converted into a website address that the compromised machine visited to report in or to update the malicious code they harboured.
Very few comments posted to the Instagram account had the key characteristics - suggesting that Turla's creators were testing or refining the control system.
Mr Boutin said using social media in this way made "life harder for defenders".
"Firstly, it is difficult to distinguish malicious traffic to social media from legitimate traffic," he wrote. "Secondly, it gives the attackers more flexibility when it comes to changing the C&C address as well as erasing all traces of it."
Mr Boutin added that he had been in touch with Mozilla, which was working on ways to stop extensions for Firefox being compromised in this way.


A 16-year-old girl accused of possessing a guide to making bombs has been released on bail after appearing in court accused of terror offences.

The teenager, from Manchester, was allegedly found with a copy of a document known as the Anarchist Cookbook.
She appeared at Manchester Youth Court accused of two offences under the Terrorism Act 2000.
She was granted bail but was told she must observe a curfew.
The girl must also report to police three times each week and is forbidden from applying for a passport.
In addition, she must remain in England or Wales.
It is alleged that, on or before 3 April, the girl was in possession of information of a kind likely to be of use to a person preparing or committing an act of terrorism.
As well as the Anarchist Cookbook, she was alleged to have possessed a second document, described as "a recipe for explosives".
Wearing a green parka jacket and headscarf, she sat before the district judge flanked by her mother and an uncle.
No pleas were entered, and she was released until a further hearing planned for 26 August.


Tolls for the Humber Bridge are to be frozen for the next five years, officials have announced.

Motorists pay £1.50 for a one-way car journey across the bridge or £1.35 for drivers using an electronic tag.
The Humber Bridge Board said there would be no increase until 2021 despite plans to install a glass lift at the bridge and create a visitor centre.
Chairman Rob Waltham said the toll had been "significant in growing the Humber economy".
A planning application for the proposed tourist development at the site was submitted in June.
Project costs have not been released by the board but Bridge Master Peter Hill said it would be financed by the bridge board and "not be funded from bridge tolls".
The tolls were halved in April 2012 after the government cut £150m from the bridge's outstanding debt.
Source: Humber Bridge Board