U.S. infrared satellite detected a heat flash over the Sinai at the time the Russian plane Airbus A321 went down, reports CBS News citing the US Defense Department.

According to US intelligence, the flash indicates the jet broke as a result of a blast on the board - it could be an explosion in the fuel tanks or bombs. Still the possibility of engine explosion or a mechanical failure is not ruled out.

Prior to that, the US private intelligence company Stratfor has published an analytical report on the possible causes of the Russian plane crash, raising the possibility that a bomb on board brought it down.

Reminder: Oct 31, being en route to St. Petersburg from Sharm el-Sheikh, the Russian A321 airliner, the Kogalymavia airline, crashed with 224 people on board, four of them Ukrainians. Egyptian authorities say technical problems are the most likely cause of the crash.