Islamic State forces 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.

COMMERCIAL BREAK
SCROLL TO CONTINUE READING

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 defence 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 Islamic State, 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.The US military is testing to see if a chemical agent may have been used in a rocket attack in Iraq by Islamic State that came within hundreds of yards (meters) of US forces.

The United States has also observed repeated Islamic State attacks over the past year or so against Iraqi troops, Kurdish forces and Syrian soldiers, a second US official said. But the official stressed there had not been such attacks against the U.S. forces in Iraq, who number at least 4,400.