Militant fighters of the Islamic State (ISIS) radical group 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, officials said.
No US troops were hurt or have displayed symptoms of exposure to a mustard agent, CNN reported on Wednesday, citing several US officials.
An official source said that the agent had “low purity and was poorly weaponised”.
Another US official called the attack “ineffective”, the network reported.
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 has not issued any statements on the incident yet.
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