Algerian PM confirms in phone call to Cameron end of hostage crisis
Prime Minister David Cameron has been told in a phone call from his Algerian counterpart that the hostage crisis has been ended, Downing Street has said.
Earlier, Defence Secretary Philip Hammond blamed militants for the deaths of hostages in Algeria amid reports that seven hostages and 11 captors had died in an army assault.
The UK ambassador is in nearby In Amenas to give consular support.
A meeting of the government's emergency committee, Cobra, is under way.
'Appalling and unacceptable'
Mr Hammond said the government had received information that the hostage situation had been brought to an end and that there had been "further loss of life".
"We're pressing the Algerians for details on the exact situation and the numbers that have been killed and, if any, the numbers rescued," he said, before adding that the deaths were "appalling and unacceptable".
"We must be clear that it is the terrorists that bear sole responsibility for it."
The Foreign Office said it had been told by the Algerian authorities the military phase had come to an end "but they are still seeking to make the site secure".
"We are continuing our work to establish the status of all the British nationals," a spokesman added.
The BP Group chief executive, Bob Dudley, said the company was "unable to confirm the location or situation" of four employees at the plant.
"While not confirmed, tragically we have grave fears that there may be one or more fatalities within this number," he said.
In a statement, the company said of its employees at the site, 14 were now confirmed safe and secure. Two had sustained injuries, but these were not life-threatening.
The British ambassador, Martyn Roper, along with a small consular and political team, travelled to In Amenas, the town close to the plant, to give consular support.
Militants, who have held the site for four days, had told a Mauritanian news agency they had seven foreign hostages.
The hostage-takers initially attacked two buses carrying foreign workers on Wednesday. A Briton and an Algerian reportedly died in that incident.
The militants then took Algerians and foreign workers hostage at the complex, which is part-operated by BP.
'Glad to be out'
A number of freed Britons were been pictured on Algerian TV, where one said he was impressed by Algerian soldiers who battled with the militants.
One of the freed hostages, Alan Wright from Portsoy, in Aberdeenshire, has returned to the UK.
Speaking to BBC Scotland he said: "I'm back in the UK with my wife and looking forward to seeing the rest of my family once I get home and also thinking of all my friends not yet safe."
Another man held hostage, Iain Strachan, 38, from Howwood in Renfrewshire, said he was "very relieved to be out", adding: "Obviously we still don't really know what's happening back on site.
"So, as much as we're glad to be out, our thoughts are with colleagues who are still there at the moment."
He said the Algerian army's assistance had been "fantastic".
"I've never been so relieved as when they came and got us off site," he said. "We thank them very much for that."
Mr Strachan was interviewed on a bus alongside Darren Matthews, 29, from Teesside.
Mr Matthews said: "I am relieved to be going to see friends and family. I feel safe at the moment but I won't feel 100% happy until I'm back in the UK, when I am back with my family.
"My heart goes out to the guys that are still there and hopefully everyone comes home safe because, at the end of the day, it's only work. No-one should have to go through that just for a job."
Another freed Briton, Martin Johnson from Todmorden, praised the Algerian forces. He said: "I think they did a fantastic job, I was very impressed with the Algerian army. I feel sorry for anybody who's been hurt."
And an unnamed Briton who was also freed said the "gendarmes did a fantastic job, kept us all nice and safe and fought off the bad guys. I never really felt any danger, to be honest".
Other Britons who have been freed include Mark Grant, from Grangemouth, and Stephen McFaul, 36, from Belfast.