The hostage crisis in Algeria is still going at a gas plant in the Sahara Desert which was taken over on Wednesday by an Islamist group calling itself the Battalion of Blood.
British prime minister David Cameron has told the British parliament that it remains a fluid and dangerous situation. US secretary of state Hillary Clinton has described it as "extremely difficult and dangerous".
The Algerian state news agency says it is now known at least 12 foreign and Algerian hostages have been killed since the militants attacked and occupied the In Amenas plant in eastern Algeria.
Mauritania's ANI news agency is quoting the militants as saying they still have seven live hostages: three Belgians, two Americans, one Japanese and a Briton.
US defence secretary Leon Panetta says the US is doing everything it can to keep the hostages still in captivity safe.
France and the United States have each confirmed that one of their citizens is among the dead. Eighteen terrorists are reported dead.
The APS news agency says those freed so far include 573 Algerians and about 100 of 132 foreigners.
The agency says the installation has been put out of action to avoid the risk of an explosion.
At least four foreigners died when Algerian troops moved in on Thursday, after the kidnappers tried to shift some of their captives from the facility.
An Irish hostage who escaped at the time has told his wife the army bombed four jeeps and probably killed many of the hostages, who had explosives tied around their necks.
Meanwhile, one of the companies jointly operating the plant, BP, says hundreds of personnel from international oil companies were evacuated from Algeria on Thursday and many more will follow.
BP operates the gasfield jointly with Statoil of Norway and the Algerian state oil company Sonatrach.
More attacks threatened
A spokesperson for the group behind the attack says it will carry out further operations. ''We will strike where it is least expected,'' he says.
A statement purporting to come from the kidnappers says the raid was carried out in retaliation for the French intervention in neighbouring Mali just over a week ago
But the BBC's security correspondent says the kidnapping was a complex operation which is unlikely to have been planned and carried out in so short a time.
The Tigantourine gas facility is about 1300 kilometres south-east of the capital, Algiers, and not far from the Libyan border.