Three British nationals have been confirmed killed during a hostage crisis at a gas plant in Algeria, and a further three Britons along with a resident of Britain are believed to have died, Prime Minister David Cameron said on Sunday.
Islamist militants seized the remote compound in the Sahara desert before dawn on Wednesday, taking a large number of hostages. Details are still emerging of what happened when the Algerian army launched an assault to end the siege on Saturday.
"Tragically we now know that three British nationals have been killed and a further three are believed to be dead and also a further British resident is also believed to be dead," Cameron said in a televised statement.
"The priority now must be to get everybody home from Algeria ... and I've spoken this morning to our ambassador who is in Algiers and this morning will be going again to the south of the country to help coordinate that absolutely vital activity."
Foreign Secretary William Hague said shortly after Cameron spoke that 22 Britons who had been caught up in the hostage drama had flown home on charter flights organised by the government or by BP.
Cameron had told parliament on Friday he was "disappointed" Algeria had given him no advance warning of an operation to rescue hostages at the plant, but on Sunday he thanked Algeria for its actions.
"Now of course people will ask questions about the Algerian response to these events, but I would just say that the responsibility for these deaths lies squarely with the terrorists who launched this vicious and cowardly attack," he said.
"We should recognise all that the Algerians have done to work with us and to help and coordinate with us. I'd like to thank them for that. We should also recognise that the Algerians too have seen lives lost among their soldiers."
Asked whether the threat from militant groups in North Africa was as serious as the one that had once existed in Afghanistan, Cameron said: "It is different in scale but there are similarities.
"What we face is an extremist Islamist violent al Qaeda-linked terrorist group, just as we had to deal with in Pakistan and Afghanistan, so the world needs to come together to deal with this threat in North Africa."