The U.S. intelligence community intercepted a signal from an ISIS-affiliated group in the Sinai Peninsula before a Russian airliner crashed there Saturday. The message warned of “something big in the area,” two officials told The Daily Beast. An adviser familar the U.S. intelligence said a call was made between members of Wilayat Sinai, which a U.S. official said Thursday was one of the “most potent” branches of ISIS. The conversation did not mention downing an airplane, but a defense official said comments could be tied to the crash. It is not known when the call was placed.

Also, U.S. defense officials said Russian strikes targeted Raqqa, Syria, the capital of the self-proclaimed Islamic State, on Thursday, raising questions about whether Russia was conducting retaliatory attacks in response to the crash.

The Department of Homeland Security said Friday it will “enhance” security measures for commercial flights entering the U.S. from overseas. (The U.S. has not flown into Sinai since March.)

— Nancy A. Youssef