The British government is prepared for "bad news" as the hostage situation in Algeria is "ongoing," a spokesman said Friday.
The warning came after all-night meetings of security officials, and the cancellation of a key speech on Europe Prime Minister David Cameron had been due to give in the Netherlands.
"The terrorist incident in Algeria remains ongoing," said a Foreign Office spokesman. Unconfirmed reports said "multiple" British deaths would possibly have to be expected.
"The prime minister has advised we should be prepared for bad news," added the spokesman. He said no further details would be given in order not to "endanger the lives" of British nationals involved in the hostage crisis.