U.S. Official: Syria Mixing Chemicals for Sarin Gas

Syria has begun mixing chemicals that can be used to make deadly sarin gas, a U.S. official told AFP Monday, amid fears that President Bashar Assad's forces could attack rebels with chemical weapons.

"We've picked up several indications which lead us to believe that they're combining chemical precursors," the official said, on condition of anonymity, adding that the operation was apparently aimed at making sarin.

Earlier, CNN said that Washington believed that Assad's regime was considering the feasibility of putting sarin into artillery shells for use in a limited chemical strike against opposition soldiers, the report said.

U.S. officials stressed to the news channel that they did not believe that Assad had made a final decision on mounting such a strike.

Sarin, used in two terror attacks in Japan in the 1990s, is a man-made nerve agent which can cause convulsions, respiratory failure and death.

The intelligence appeared to explain a series of fresh warnings issued by Washington that the use of chemical weapons by the Assad government would cross a "red line" and invite unspecified U.S. action.