China's Foreign Ministry said it is investigating reports that a chlorine canister bearing the name of the country's biggest arms maker was shown in footage believed to document a gas attack in Syria this month.

Attacks this month in several areas in Syria share characteristics that have led analysts to believe that there is a coordinated chlorine bomb campaign, with growing evidence that the government side is dropping the weapons.

In the rebel-held village of Kfar Zeita in the central province of Hama, 125 miles (200 km) north of Damascus, opposition activists uploaded video of people choking and being fed oxygen following what they said were bombs dropped from helicopters on April 11 and 12.