At least four people have been killed in a US raid in Baghdad's Shia stronghold of Sadr City amid fresh fighting between Shia fighters and Iraqi security forces.

Six people were also wounded in the air raid after midnight near the Al-Albaith mosque.

Sadr City is a stronghold of Muqtada al-Sadr, the Shia leader whose Mahdi Army militiamen are fighting Iraqi and US forces.

Residents of the sprawling eastern Baghdad district which has been under vehicle curfew since March 28 reported sporadic firefights punctuated by mortar fire through the night and into the morning.

Around 70 people have been killed and scores wounded since fresh clashes broke out in Sadr City on Sunday.

Among those killed were three members of a family who were having breakfast when a mortar round smashed into their home.

The US military says it is chasing "criminals" firing rockets into Baghdad and the heavily-fortified Green Zone where the Iraqi government and US embassy are based.

Small arms fire

It said on Thursday that 13 "criminals" were killed in operations the previous 24 hours in Sadr City and northwest Shuala neighborhood, another Mahdi Army stronghold.

In one incident, a combined US-Iraqi checkpoint was attacked from a nearby rooftop by small arms fire and troops retaliated, killing one of the attackers, a military statement said.

Another four fighters were killed when troops retaliated after they were attacked with rocket-propelled grenades at a checkpoint, while a air raid on Wednesday night killed four armed men after they attacked Iraqi troops.

At least 12 US soldiers have been killed in Baghdad since Sunday, most of them in Sadr City, according to an AFP tally based on American military statements.

PHOTO CAPTION

Residents cry as they wait to claim the bodies of their relatives killed during clashes in Baghdad's Sadr City April 9, 2008.

Al-Jazeera