Islamic State militants used chlorine gas during fighting with security forces and Shiite militiamen last month north of Baghdad, Iraqi officials said on Friday.
The use of chlorine gas as a weapon adds a new concern to the turmoil in the country. The reports, if confirmed, would be the first time the Sunni extremists attempted to use chlorine since their blitz earlier this year that seized large chunks of territory in northern Iraq and neighbouring Syria.
Three Iraqi officials told AP that the Islamic State group used bombs with chlorine-filled cylinders during clashes in late September in the two towns.
About 40 troops and Shiite militiamen were slightly affected and showed symptoms consistent with chlorine poisoning.
