In the US News today
The US Pentagon reported that the satellite saw two heat events, one while the airplane was at altitude, and one upon impact with the ground.
"There is a definite feeling it was an explosive device planted in luggage or somewhere on the plane," the official, who is familiar with the latest U.S. intelligence analysis of the crash said today.
Based on the same intelligence, the U.S. belief is that ISIS or an ISIS-affiliated group is responsible for the attack, the official said.
The British government announced Wednesday that it had "become concerned that the plane may well have been brought down by an explosive device."
A UK aviation team is traveling to inspect the Sharm airport to look at whether there were proper security measures at the airport and the various scenarios, by which, an explosive device could have made it to the Russian airliner "including a person or in cargo," according to the British transport minister.