Philip Hammond said it is likely the airliner, which was carrying 224 people, was brought down by a follower of the terrorist group.

He said: "It may have been an individual who was inspired by ISIS who was self-radicalised by looking at ISIS propaganda and was acting in the name of ISIS without necessarily being directed."

Mr Hammond's comments came as Russia also believes the plane was blown up by a bomb, according to US sources who reportedly intercepted Russian communications.

The Pentagon's intercepts are among other pieces of evidence leading US officials to believe the bomb was planted on Metrojet Flight 9268 - which exploded shortly after taking off from Sharm el-Sheikh.

All 224 people on board the plane - bound for St Petersburg, Russia - were killed.

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