Tests show mustard gas traces in Islamic State attack

Washington (CNN)Fragments from an ISIS mortar fired on Kurdish forces near Makhmour, Iraq, earlier this month tested positive for sulfur mustard agent during a field test conducted by the U.S. military, Brigadier General Kevin Killea, chief of staff for operations for the global coalition against ISIS, told reporters at the Pentagon Friday.

“We were able to take the fragments from some of those mortar rounds and do a field test…on those fragments, and they showed the presence of HD, or what is known as sulphur mustard”, Killea said.

Killea cautioned that this was a “presumptive field test”, and further analysis is needed to possibly determine the source of the chemical weapon.

The attack occurred in the town of Makhmour in northern Iraq near the front lines of the Kurdish forces’ fight against the Islamic State, according to Killea, who briefed reporters at the Pentagon on Friday.

“So I would ask everybody’s patience on that until the… full tests are returned”, he added.

Diplomatic efforts by the U.S. and Russian Federation following a chemical weapons attack in Syria in 2013 led to the removal or destruction of the Syrian government’s chemical weapons stockpiles.

The initial tests have to be backed up by full testing, and that could show, among other things, whether the fragments were part of munitions that contained the chemical weapon and were not tampered with.

Regardless, he said, “we really don’t need another reason to hunt down [the Islamic State] and kill them wherever we can”.

U.S. officials have expressed persistent concerns about the possibility that IS would locate and use chemical weapons in its ongoing campaign to take control of more territory across Iraq and Syria.