At least five US soldiers have been wounded when their convoy was ambushed with rocket-propelled grenades and small-arms fire in the Iraqi city of Mosul.
After the clash, troops blocked off the section of town where the fighting had been.
Witnesses said two vehicles were left burning and that others were damaged.
The spate of attacks in the past week in Mosul, Iraq's third-largest city, has raised concerns among US military commanders that the insurgency is now spreading into that region from its main stronghold in the Sunni Triangle, to the west and north of Baghdad.