Sources from the global chemical watchdog say Islamic State (IS) militants used sulphur mustard (mustard gas) in an attack on Iraqi Kurdish forces last year. Lab tests came back positive for the substance after Kurdish soldiers fell ill on the battlefield. The BBC reports: The Organisation for the Prohibition of Chemical Weapons (OPCW) was sent samples after 35 Peshmerga fighters became ill near Irbil in August. On Monday, the sources said the samples tested positive for sulphur mustard. If confirmed, it would be the first known use of chemical weapons in Iraq since the fall of Saddam Hussein. OPCW experts recently concluded that sulphur mustard was used in August in neighbouring Syria, during fighting between IS and rebel forces. Sulphur mustard – commonly known as “mustard gas” although it is liquid at ambient temperature – is a powerful irritant and blistering agent which causes severe damage to the skin, eyes and respiratory system and internal organs. ‘Black liquid’ The OPCW’s report does not apportion blame for the attack in Iraq on 11 August, sources in The Hague told the Reuters and AFP news agencies. But when the Kurdistan Regional Government’s ministry of Peshmerga affairs first reported the incident, it made [...]