BAGHDAD, Iraq (CNN) -- An individual in an Iraqi army uniform opened fire on U.S. troops in Nineveh province Wednesday, killing two soldiers and wounding six others, a U.S. military spokesman said.The U.S. military has not confirmed the identity of the shooter, but initial reports indicate the shooter was an Iraqi soldier, the military said in a statement. The gunman was killed in the ensuing exchange of fire.
An Interior Ministry official said an Iraqi soldier in a joint U.S.-Iraqi patrol opened fire on a group of U.S. soldiers in the same convoy after one of the American troops slapped an Iraqi soldier.
The shooting occurred in the al-Zanjili area of Mosul, about 261 miles (420 kilometers) north of Baghdad, the ministry official said. The incident occurred about 5:30 p.m., officials said. The ministry official said four U.S. soldiers were killed and three were wounded.
The incident is under investigation, the U.S. military said, but did not confirm any details of a reported altercation.
Earlier Wednesday, a car bomb exploded near an Iraqi police patrol in central Baghdad, killing four people and wounding 14 others, an Interior Ministry official said. The attack took place in Naser Square around 9:40 a.m.
Meanwhile, a roadside bomb exploded near a car in a Shiite section of northeastern Baghdad, wounding seven civilians. A car bomb also exploded in the al-Shaab neighborhood of northeastern Baghdad, killing two people and wounding 10, an Interior Ministry official said.