WASHINGTON - US authorities believed that the extremist group, the Islamic State (IS), likely used mustard agent against Kurdish forces in Iraq earlier this week, the Wall Street Journal reported Thursday.
It was the first indication that the militant group had obtained banned chemicals.
Quoting senior US officials, the Journal said that US intelligence agencies believed that the IS had at least a small supply of mustard agent even before this week's clash with Iraqi Kurdish fighters.
On Wednesday, authorities said about 60 Iraqi Kurdish fighters participating in fights against the IS in northern Iraq were reported to have suffered injuries to their throats consistent with a chemical attack.
US intelligence communities have long been concerned that the IS, now in control of a wide swaths of Syrian territory, would find hidden storage of chemical weapons possibly left after conflicts between Syrian government and anti-government rebels.
The Islamic State could also have obtained the mustard agent in Iraq, the Journal cited US senior officials as saying.