US Trying to Determine What Chemical ISIS Used in Iraq Attack

The U.S. military is trying to determine what chemical the Islamic State group used against Iraqi government forces last weekend, the commander of anti-IS coalition ground forces said Wednesday.

Maj. Gen. Joseph Martin told reporters via video link from Baghdad that Iraqi forces were treated after a strike in western Mosul. He said no one was "significantly impacted."

The Organization for the Prohibition of Chemical Weapons has said IS militants previously have used sulfur mustard gas. Wilson said that in the past, IS has demonstrated a "low-grade capability" with chemical weapons.

On Sunday, Iraqi Defense Ministry spokesman Brig. Gen. Yahya Rasool told The Associated Press that six soldiers suffered breathing problems and were treated in a nearby field clinic.

Martin on Wednesday wouldn't say whether U.S. or Australian military advisors were in the vicinity at the time. He said the attack was delivered by "indirect fire" — a term typically used to describe mortar or rocket fire.

The attack came a day after an Iraqi military officer said IS militants launched a chlorine gas attack by rocket in the al-Abar neighborhood, a newly liberated area in western Mosul.

IS has lost more than half the territory it once controlled in Iraq. It's now fighting to defend a cluster of western neighborhoods in Mosul, the second-largest city. It is the last significant urban area the group holds.