First on CNN: U.S. officials believe ISIS planted bomb on Russian plane

(CNN)The latest U.S. intelligence suggests that the crash of a Russian passenger jet in the Sinai over the weekend was most likely caused by a bomb on the plane planted by ISIS or an ISIS affiliate, according to a U.S. official familiar with the matter.

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But the official stressed a formal conclusion has not been reached by the U.S. intelligence community. "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, told CNN. More...