An attack at a police station in northern Iraq killed one US soldier and an Iraqi interpreter, the US military said, but did not confirm Iraqi reports that local police opened fire on US troops.
Iraqi security sources reported the shooting took place during a visit by US soldiers and their interpreters to a police station in Mosul, Iraq's most violent city.
According to the sources, two members of a police force responsible for guarding bridges opened fire at the group of soldiers and then fled.
The US military said in a statement early on Wednesday that three soldiers and one interpreter were wounded in the attack. Another US soldier died after being taken to a combat hospital, and another Iraqi interpreter was killed.
Two US soldiers were shot dead by an Iraqi soldier in Mosul in November.
Violence in Iraq has dropped sharply from its peak in 2006 and 2007, but car bombs, roadside explosions and assassinations continue to hit Mosul and surrounding Nineveh province daily.
US and Iraqi forces launched a new military campaign last week in Mosul, seen as a hold out for al Qaeda and other Sunni Islamist groups, and have arrested scores of suspects since then.