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The latest news and analysis on the U.S. and several Arab nations striking ISIS targets in Syria.
(CNN) – The militant fighter seen in a horrific video showing the beheading of American journalist James Foley is likely from Britain.
"We have not identified the individual responsible on the video, but from what we've seen it looks increasingly likely that it is British citizen. This is deeply shocking," Prime Minister David Cameron said Wednesday.
A former hostage told The Guardian newspaper that he recognized the voice. He called him John, saying he was one of three British members of ISIS who guards Western captives.
Authorities will "be examining the voice recording very, very carefully and trying to match it up with people who perhaps have travelled from London – it sounds like a London accent – that they know about who have traveled to Syria," said CNN terrorism analyst Paul Cruickshank.
"There are 400 British extremists who traveled to Syria or Iraq to link up with jihadist groups, and there are 250 back in the UK ... so a lot of concern that some of these individuals could actually come back and launch strikes," said Cruickshank.
For more of our interview with CNN terrorism analyst Paul Cruickshank, check out the videos below.