David Cameron is holding crisis talks in Downing Street to lead the Government's response to a the murder of a US journalist by an Islamic State (Isis) militant thought to be from Britain.
The Prime Minister cut short his holiday after a video was released overnight showing what appears to be a British man beheading an American reporter, James Foley, in what he claims is a revenge killing for the ongoing US air strikes in Iraq.
Mr Cameron will be briefed by senior intelligence officials as intelligence services try to piece together evidence that could identify the killer.