Iraqi troops tightened their grip on the Baghdad militia bastion of Sadr City on Wednesday, a day after moving into the Shiite district for the first time in eight weeks, officials said.

More Iraqi soldiers were seen deploying in the district and dozens of blasts were heard as they carried out controlled explosions of roadside bombs planted by militiamen during deadly clashes with US troops, residents said.

The Shiite radical movement of anti-American cleric Moqtada al-Sadr had agreed that its Mahdi Army militia would offer no resistance to the Iraqi troops' deployment under a truce deal it reached with the government on May 10.

"We want the army to continue its deployment and respect human rights and ensure the dignity of the people." Sadr spokesman Salah al-Obeidi told AFP in the central shrine city of Najaf. "We cooperate with the army."

Obeidi said the Sadrists wanted the military to do their job "neutrally."

"We see on both our side and the other (government) side real will to implement the agreement and resolve all issues in Sadr City," he said, alluding to the lack of jobs and services in the impoverished neighbourhood of some two million people.

Hospitals in Sadr City said they admitted no casualties from any violence in the district overnight, in sharp contrast to the past weeks of violence when dozens of dead or wounded were admitted daily.

The US military said that the Iraqi troop deployment was planned and executed by the Iraqi army itself.

"The operation is to protect the people while setting conditions for sustainable security and increase humanitarian assistance, economic growth and essential services," a statement said.

Much of the fighting had centred around a huge concrete wall that the US military has been building to cut off one third of the Sadr City in a bid to prevent the flow of heavy weapons to the rest of Baghdad.

Work on the wall became a key issue for the militiamen who repeatedly attacked those constructing it under US protection.

The clashes in Sadr City erupted after Prime Minister Nuri al-Maliki ordered a crackdown on militias, starting in the main southern city of Basra, in late March.