ERBIL (Reuters) - Kurdish authorities said on Friday they were investigating another suspected chemical attack by Islamic State militants against peshmerga fighters in northwestern Iraq this week.
Dozens of peshmerga and civilians were treated for nausea and vomiting after homemade rockets, that appeared to have contained a chemical substance, were fired at them in the Sinjar area on Feb. 25, the Kurdistan Region Security Council said on its official Twitter account.
The U.S.-led coalition is helping with the investigation, the security council said.
Earlier on Friday, Jabbar Yawar, the secretary general of the peshmerga ministry, told Reuters the substance was probably chlorine, a choking agent whose use as a chemical weapon dates back to World War One.
It is banned under the 1997 Chemical Weapons Convention.
The Kurds have previously said they have evidence that Islamic State has used chlorine against the peshmerga on a number of occasions, as well as mustard gas.
"If confirmed this will be eighth ISIL weaponised chemical attack against Peshmerga. ISIL tactics continue to become more sophisticated," the security council said.
A Source at the Organisation for the Prohibition of Chemical Weapons (OPCW) confirmed this week that laboratory tests had come back positive for sulphur mustard, after about 35 peshmerga became ill on the battlefield last August.
Reporting by Isabel Coles; Editing by Louise Ireland