US 'deeply concerned' by Syria 'toxic gas' claim

WASHINGTON (AP) -- The White House says it's "deeply concerned" about reports that chemical weapons were used by Syria's government against civilians.

White House spokesman Josh Earnest says the U.S. strongly condemns any use of chemical weapons and says the Obama administration is urgently working to gather information. Earnest says the U.S. is asking the U.N. to investigate and wants a Security Council debate.

Syrian anti-government activists say the regime carried out a toxic gas attack Wednesday, killing at least 100 people, but the government has denied that.

The attack coincided with a U.N. chemical weapons team's visit to investigate previous chemical weapons allegations.

The U.S. concluded in June that Syria probably used chemical weapons. That led to a U.S. decision to approve sending weapons to the rebels for the first time.