The UN ’s Organisation for the Prohibition of Chemical Weapons ( WHO ) has said that ISIS is likely to be using chemical weapons against its enemies in Iraq and Syria . The OPCW has been investigating 11 alleged chemical weapon attacks reported to it by the Syrian Government . In at least one case , blood samples indicated exposure to the deadly nerve agent sarin or a sarin - like substance . The Syrian Government , which has previously been held responsible for hundreds of chemical weapon - related deaths , claims to have handed over all of its chemical weapon stockpiles . Opposition group leaders allege that forces loyal to President Bashar Al-Assad are responsible for using the illegal gas, while the government charges it was opposition groups including the Islamic State (ISIS) who are responsible. Iraqi and US officials have said that ISIS is known to have used former government stockpiles and laboratories , and also has access to experts , allowing it to pursue a chemical weapons programme .
The UN ’s Organisation for the Prohibition of Chemical Weapons ( WHO ) has said that ISIS is likely to be using chemical weapons against its enemies in Iraq and Syria . The OPCW has been investigating 11 alleged chemical weapon attacks reported to it by the Syrian Government . In at least one case , blood samples indicated exposure to the deadly nerve agent sarin or a sarin - like substance . The Syrian Government , which has previously been held responsible for hundreds of chemical weapon - related deaths , claims to have handed over all of its chemical weapon stockpiles . Iraqi and US officials have said that ISIS is known to have used former government stockpiles and laboratories , and also has access to experts , allowing it to pursue a chemical weapons programme .