Iraqi Prime Minister Nuri al-Maliki on Wednesday gave Shi'ite fighters in the southern province of Maysan a seven-day deadline to surrender.

Iraq's hard-line Shi'ite leader, Moqtada al-Sadr, said on Friday he plans to form a new wing of his powerful movement to battle United States forces.

More than 900 people have been killed in clashes between militiamen and security forces in Baghdad's Sadr City, which broke out last month, a senior Iraqi official told reporters on Wednesday. "There were 925 martyrs in Sadr City and 2 605 others have been wounded", said Tehseen Sheikhly, a spokesperson for the government's Baghdad security plan.

The United States military said on Monday it had killed 22 fighters who attacked an Iraqi checkpoint in north-eastern Baghdad under cover of an overnight dust storm. The attack was one of the biggest in weeks, and indicated some fighters had defied an order by Shi'ite cleric Moqtada al-Sadr to observe a ceasefire.

Militants bombarded Baghdad's Green Zone with rockets on Sunday, taking advantage of the cover of a blinding dust storm to launch one of the heaviest strikes in weeks on the fortified compound. The strikes appeared to defy a renewed call for a ceasefire by Shi'ite cleric Moqtada al-Sadr, which has seen many of his masked gunmen leave the streets of the Sadr City slum.

Iraqi Shi'ite cleric Moqtada al-Sadr pulled back from confrontation with the government on Friday, asking his followers to continue to observe a shaky ceasefire and not to battle government troops. Sadr said his recent threat of "open war" was directed only at United States forces, not the Iraqi government.

Shi'ite cleric Moqtada al-Sadr on Saturday threatened an "open war" against the Iraqi government unless it halted a crackdown by Iraqi and United States security forces on his followers. The spectre of a full-scale uprising by Sadr sharply raises the stakes in his confrontation with Prime Minister Nuri al-Maliki.

United States and Iraqi forces killed 13 gunmen in clashes and air strikes overnight in the Baghdad stronghold of cleric Moqtada al-Sadr, who said the US would remain his enemy until the "last drop of my blood". Authorities eased a blockade on Saturday in the Sadr City district of eastern Baghdad that had trapped residents in the slum for two weeks.

President George Bush on Thursday announced a suspension of United States troop withdrawals from Iraq this summer to allow the military to reassess the security situation. The announcement came amid a spike in violence in Iraq in recent weeks.

United States air strikes killed 10 people in the eastern Baghdad militia stronghold of Sadr City, Iraqi police said on Thursday, but street fighting eased after four days of clashes that have killed close to 90 people. The Sadr City slum has since Sunday been the focal point of battles between black-masked Mehdi Army militiamen and security forces.