No 'direct proof' of terror in Egypt crash

US Director of National Intelligence James Clapper says he knows of no "direct evidence" that terrorism was to blame for the weekend plane crash of a Russian passenger plane in Egypt.

Speaking at a Washington defence summit on Monday, Clapper said it was "unlikely" that the Islamic State group had the capacity to carry out such an attack, but added "I wouldn't rule it out."

"We don't have any direct evidence of a terrorist element yet," he said.