A U.S. service member was killed on Saturday “during a controlled detonation of unexploded ordnance” in northern Iraq, U.S. Central Command said.

The unexploded ordnance was from a “downed Iranian one-way attack drone,” Central Command said in a statement released Sunday.

The death of the U.S. service member in Iraq follows in the wake of two U.S. service members killed in action on Friday in an Iranian ballistic missile and drone attack on U.S. and partner forces in Jordan, U.S. Central Command announced.

Four more troops had to be medically evacuated to hospitals in Jordan.

Those four service members have since been discharged, the command added.

“Other personnel who were evaluated for minor injuries have returned to duty,” the release stated.

U.S. Central Command originally noted that a third U.S. service member was missing, however, CENTCOM announced today that “After a thorough search, U.S. military personnel found unidentified remains at the location earlier today. An examination process to verify the remains is ongoing.”

U.S. Central Command is withholding the identities of the dead until 24 hours after the service members’ next of kin have been notified.

Additional information about the exact location of the attack had not been provided as of publication.

The latest casualties bring the toll of American troops killed in the war with Iran to 18.

Most recently, the commanding officer of the Navy’s Helicopter Sea Combat Squadron 5, Cmdr. Gabriel Edwards, was killed on July 1 when the MH-60S Sea Hawk helicopter he was aboard went down in the Arabian Sea. Three other sailors were rescued following the emergency landing.

More than 400 U.S. troops have been wounded in the campaign, which began Feb. 28.