Several alleged gas attacks on Syrian opposition groups this month have raised fears that forces loyal to embattled President Bashar Assad are continuing to use chemical weapons. On Tuesday, opposition groups uploaded videos of people choking and convulsing after a substance rebels say is chlorine gas was fired on civilians. One boy died in a hospital near the Turkish border despite receiving treatment, The Daily Telegraph reports. “We have indications of the use of a toxic industrial chemical — probably chlorine — in Syria this month in the opposition-dominated village of Kfar Zeita,” State Department spokeswoman Jen Psaki said Tuesday. “We’re examining allegations that the government was responsible.