ISIS Has Used a Troubling Weapon Chemical mortar shell is found By John Johnson, Newser Staff Posted Jul 18, 2015 6:33 AM CDT 62 comments Comments An Islamic State militant fires a mortar against Kurdish fighters in Syria in this file photo. (Militant website via AP) (Newser) – ISIS appears to be learning how to make—and use—chemical projectiles. The allegation isn't based on just anecdotal evidence: Authorities got their hands on an unexploded shell fired by Islamic State militants in Iraq last month, reports the New York Times. The device was crude, hence the failure to explode, but it was leaking a chemical that caused several Kurdish fighters to get sick. A French ordnance technician says the chemical is probably chlorine, though test results were still pending. ISIS has used chemicals previously in suicide bombings, but the leap to placing them in shells fired across large distances is a significant one, says the newspaper. ISIS also used "makeshift chemical projectiles" in Syria late last month, according to a Kurd militia there and a rights group monitoring the fighting, reports Reuters. About a dozen Syrian Kurd fighters with the YPG militia exposed to the gas "experienced burning of the throat, eyes and nose, combined with severe headaches, muscle pain and impaired concentration and mobility." YPG forces say they've captured gas masks from ISIS fighters in recent weeks.