BAGHDAD (AP) — A coalition service member was killed Saturday by enemy fire in northern Iraq, the Pentagon said in a statement.

A U.S. official told The Associated Press the individual was an American stationed at the Makhmour base outside the Islamic State group-held city of Mosul.

The attack was an "indirect fire attack," specifically rockets, the official said. The official spoke on condition of anonymity as he wasn't authorized to brief the media.

Two Iraqi commanders stationed at the base also reported a rocket attack Saturday, but denied anyone had been hurt or killed.

The U.S.-led coalition has reported that the build-up of Iraqi troops at Makhmour in preparation for an assault on Mosul has brought a spike in the frequency of such indirect fire attacks.

The last U.S. service member killed in Iraq was in October 2015.