China's biggest arms maker said on Friday it had never exported any chlorine gas or cylinders to Syria after reports that chlorine gas cylinders used in a suspected toxic gas attack bore the arms giant's name, "**rinco". China **rth Industries Group Corporation, or **rinco, said the logo printed on the canister was **t the same as its standard engraving. "**rinco is greatly concerned about the incident of chlorine gas attack in Syria as well as its aftermath and has since looked into all our past contracts and historical files," a statement said. "**rinco would hereby solemnly declare, based on our investigations, that we never exported any chlorine gas or its cylinders to Syria." Opposition activists in the rebel-held village of Kfar Zeita in the **rth of Syria's Hama province uploaded a video of people choking and being fed oxygen after what they said were bombs dropped from helicopters on April 11 and 12.