From Phil Stewart and David Alexander, Reuters:  In Brussels, the NATO alliance was "concerned by reports of the possible use of chemical weapons," an official said.

"As NATO has said in the past, any use of these weapons would be completely unacceptable and a clear breach of international law, and if any side uses these weapons we would expect a reaction from the international community," the official said.

Patriot missile interceptors that NATO has sent to Turkey, a member of the alliance which borders Syria, would "help ensure the protection of Turkey against any missile attack, whether the missiles carry chemical weapons or not," the official added. (photo: Evan Vucci/Reuters)