Exclusive: Chemical weapons used by fighters in Syria - sources

By Anthony Deutsch THE HAGUE (Reuters) - Chemical weapons experts have determined that mustard gas was used in a Syrian town where Islamic State insurgents were battling another group, according to a report by an international watchdog seen by Reuters. A confidential Oct. 29 report by the Organization for the Prohibition of Chemical Weapons (OPCW), a summary of which was shown to Reuters, concluded "with the utmost confidence that at least two people were exposed to sulfur mustard" in the town o