Tests carried out by the Organization for the Prohibition of Chemical Weapons (OPCW) confirmed that Islamic State (ISIS) attacked Kurdish Peshmerga forces with mustard gas last year.
The results of the laboratory tests have yet to be officially announced, however a source from within the OPCW have confirmed that the samples tested came back positive for sulfar mustard.
35 Kurdish Peshmerga soldiers became ill after being exposed to the gas while fighting ISIS southwest of Erbil last August. The OPCW also confirmed last October that mustard gas had also been used in neighbouring Syria.
It isn’t yet clear if ISIS had looted some Iraqi or Syrian stockpile of mustard gas or had developed the agents themselves.