US and Iraqi forces killed at least 13 militiamen in clashes and air strikes overnight in Baghdad's Sadr City, but eased a blockade on Saturday that had trapped residents in the battle zone slum for two weeks.
Gunfire was still audible and some roads remained closed, but cars were allowed in and out of some entrances to the slum, home to 2 million poor Shias and the power base of anti-American cleric Moqtada al-Sadr and his Mehdi Army militia.
Several hundred people have died in clashes between Sadr's followers and US and Iraqi forces since late March, when Shia Prime Minister Nuri al-Maliki launched a crackdown against the militia in the southern city of Basra.
Residents described the night's clashes as among the worst since Iraqi forces launched an offensive into the area a week ago. A US military statement said at least 13 gunmen were killed in one overnight battle.
A US soldier was killed by an improvised explosive device in north-west Baghdad on Saturday. Nearly two US soldiers per day have died in April, the highest toll since September. US military spokesman Mark Cheadle said a US convoy was struck by at least 10 roadside bombs while moving to help Iraqi soldiers setting up a checkpoint in the west of Sadr City.
US forces fired at least one Hellfire missile from drone aircraft and two rounds from the main battle gun of an M1 tank at fighters who targeted them with roadside bombs, rifles and rocket-propelled grenades, the military statement added.