WASHINGTON (AP) -- The U.S. military said it is investigating an American airstrike that may have inadvertently killed Iraqi soldiers near the city of Fallujah.

In a brief statement, the U.S. military headquarters in charge of the war effort in Syria and Iraq said that one of several airstrikes it conducted Friday against Islamic State targets may have resulted in the death of Iraqi soldiers. It did not say how many may have been killed, but other officials said the Iraqis initially reported that about 10 may have died.

The U.S. statement said the airstrikes were in response to requests and information provided by Iraqi security forces on the ground near Fallujah, which is in Islamic State group control. It said the airstrikes were done in coordination with Iraqi forces. It said the U.S. will investigate what happened and has invited the Iraqis to participate.

When asked how many Iraqis may have been killed, the U.S. military command known as Combined Joint Task Force-Operation Inherent Resolve said, "The coalition is investigating the incident and will make further details available when appropriate."