Sources: Assad Dumped Chlorine From Helicopters

The US is looking into whether a toxic chemical was deployed in areas of Syria that are controlled by rebel forces seeking to oust Syrian President Bashar Assad. State Department spokeswoman Jen Psaki said today the chemical was likely chlorine, if it was used. She said officials were still trying to determine what happened in the village of Kafr Zita, but that the US takes allegations about chemicals used in combat very seriously. But several unnamed US officials and other Western diplomats tell CNN the US believes Assad's regime is responsible for the attack. "Our assessment is it is, at a minimum, concentrated chlorine dropped from helicopters," says one US official. (More Syria stories.)