ISIS militants on Tuesday fired a shell that may have contained a mustard agent onto a military base in northern Iraq used by US and Iraqi troops, CNN reported on Wednesday, citing several US officials.
No US troops were hurt or have displayed symptoms of exposure to a mustard agent, CNN said.
One official said the agent had “low purity” and was “poorly weaponized,” CNN reported. A second official called it “ineffective,” the network said.
A US defense official said troops had gone out to look at the shell after it landed on the base, which is being used to prepare an attack to retake Mosul from ISIS, CNN reported.
Two field tests were conducted after the troops saw what they thought was a suspect substance. The first test came back positive but the second test was negative, the network said.
The Pentagon did not immediately respond to a request for comment.