Five US soldiers have been killed and five others wounded in an attack on a convoy near Baghdad's main Shia Muslim district, the US military reports.
Sadr City is a dangerous beat for US patrols
Reports say the convoy came under bomb and grenade fire on the edge of Sadr City, a slum in the east of the city.
A grenade strike halted the convoy, which was then hit by a roadside bomb, witnesses told AFP news agency.
Sadr City recently became a focus of unrest among Iraq's Shia community against the US-led coalition.
Friday's attack followed an overnight clash in Sadr City between US troops and supporters of radical Shia cleric Moqtada Sadr.
A US military spokesman said a number of US soldiers had been wounded in that clash.
More than 490 US soldiers have been killed in attacks since President George W Bush declared major combat operations over in May 2003.