BAGHDAD — An American soldier in Iraq shot and killed a truck driver who did not respond to warnings to stop on a highway north of Baghdad, the U.S. military said Saturday.

The incident happened at around 2:15 a.m. Friday when the truck approached a U.S. logistics convoy that had stopped because one of its vehicles had broken down, the military said.

Soldiers flashed vehicle lights and shouted for the truck to stop, but it continued to accelerate, according to the military. A soldier thought the convoy was under attack and fired on the truck, the military said. A teenage passenger in the vehicle, identified by Iraqi officials as a brother of the driver, was not harmed.

Maj. Derrick Cheng, a U.S. military spokesman, described the killing as "tragic" and said the soldier acted in line with terms of a joint U.S.-Iraqi security deal. The soldier was unlikely to face any Iraqi prosecution because the security agreement allows for U.S. jurisdiction over American soldiers in cases when they are on duty and outside their bases.

U.S. and Iraqi forces were jointly investigating the incident, which occurred between the cities of Tikrit and Balad.

An Iraqi police officer and a medic said the truck driver was Iraqi and that he was taken to a hospital in Dujail, where he died of his wounds. They spoke on condition of anonymity because they were not authorized to speak to the media.

Such incidents were common in the early years of the war in Iraq, deepening hostility toward U.S. forces.