Assad starts firing shells filled with this stuff and the Middle East will explode like a powder keg.

Via CNN:

Syrian forces began combining chemicals that would be used to make deadly sarin gas for use in weapons to attack rebel and civilian populations, a U.S. official tells CNN.

The United States obtained intelligence over the weekend indicating this development, according to the official who had direct knowledge of the latest information.

The intelligence, the official said, came from multiple sources but declined to provide any more details about how the United states learned of it.

Sarin gas, the source said, could most readily be used to fill artillery shells.

Syrian State TV cited a Foreign Ministry official on Monday as saying the country would never use chemical weapons on its own people.

CNN reported on Sunday that U.S. intelligence is concerned about the Syrian government’s intent regarding its vast chemical weapons stockpiles after what one senior American official described as “worrying signs” of activity in “the last few days.”