The global chemical weapons watchdog has opened an emergency meeting to discuss the situation in Syria over concerns about the country’s stockpile of toxic chemicals in the wake of the overthrow of President Bashar Assad. The Organisation for the Prohibition of Chemical Weapons told Syria on Monday the country is under obligations to comply with rules to safeguard and destroy dangerous substances, such as chlorine gas, after rebels entered the capital Damascus at the weekend. Assad’s regime denied using chemical weapons but the OPCW found evidence indicating their repeated use by Syria in the grinding civil war. It also found the Islamic State group had used mustard gas.