An American airstrike may have inadvertently killed Iraqi soldiers near the city of Fallujah on Friday, according to a statement from the U.S.-led military coalition conducting the campaign against ISIS.
The statement did not say how many troops may have been killed. An investigation has been opened.
"Acting on requests and information from Iraqi security forces on the ground near Fallujah, Coalition forces conducted several airstrikes against Daesh today," the statement said. "Despite coordination with the Iraqi security forces on the ground, initial reports indicate the possibility one of the strikes resulted in the death of Iraqi soldiers."
ISIS fighters have controlled much of Fallujah and other major Iraqi cities since last summer, NPR's Philip Ewing reports. Iraqi troops with coalition forces have been preparing to try to recapture that territory.
The statement from the coalition also said, "We take great measures to prevent these types of incidents while protecting our partnered forces," and that it's not aware of any other friendly fire incidents.
U.S. officials say American warplanes based in Kuwait, Qatar, Turkey and elsewhere have flown nearly 9,000 sorties in support of Iraqi and other ground forces battling Islamic State fighters, Philip reports, but no American troops are deployed in combat alongside the indigenous forces.
Critics, led by Senate Armed Services Committee Chairman John McCain, R-Ariz., argue the U.S. should deploy special operations troops along with Iraqi and other units to serve as joint terminal attack controllers and more precisely direct the ordnance released by American warplanes.