Iraq's premier on Wednesday gave militia battling Iraqi forces in Basra 72 hours to lay down their arms, as firefights in several Shiite strongholds across the country killed almost 50 people.

Nuri al-Maliki issued the ultimatum as Iraqi troops moved for a second straight day into neighborhoods controlled by the Mahdi Army militia of Shiite cleric Moqtada al-Sadr in the southern oil city.

Sadr's powerful movement, responding to the Basra raids that the International Committee of the Red Cross said has killed at least 20 people and wounded 200, called protest rallies for Thursday "to express no confidence in the Maliki government."

US military spokesman Major General Kevin Bergner told a news conference in Baghdad that 2,000 extra Iraqi security forces had been sent to Basra to take part in an operation aimed at quelling "lawless gangs" that have taken over parts of city.

The Basra assault, which began on Tuesday, is seen as straining the ceasefire Sadr ordered his fighters to observe since last August, which the US military says has played a significant role in helping reduce overall levels of violence.

Maliki said he would allow time for those wanting to lay down their arms.

"We are not going to chase those who hand over their weapons within 72 hours," he said in a statement issued by the Basra Operational Command.

"If they do not surrender their arms, the law will follow its course."

Clashes between militiamen, Iraqi and, in some cases, US troops have also been raging in other parts of Iraq, including in Sadr City, the sprawling bastion of Sadr that is home to two million people.

An Iraqi security official said 20 people were killed and 115 wounded in the Sadr City clashes.

"Those killed and wounded included men, women and children," the interior ministry official said.

Clashes also erupted in the Shiite city of Kut, 175 kilometers (110 miles) southeast of Baghdad, where seven people were killed, police said.

Sadr called for talks to end the crisis in Basra and demanded that Maliki leave the city, where he has been personally overseeing the crackdown.

"Sadr has asked Prime Minister Maliki to leave Basra and to send a parliamentary delegation to resolve the crisis in the city," the head of the Sadr movement's political bureau, Liwa Sumaysim, told AFP in the city of Najaf.

Sumaysim added that the Sadrists have called for anti-Maliki protests in Baghdad and Amara, 365 kilometers (222 miles) south of the capital, on Thursday.

When the raids began on Tuesday, the cleric had threatened to launch nationwide protests and a civil revolt if the attacks did not end.

Bergner told the Baghdad news conference that the military assaults in Basra and Sadr City were not particularly targeting members of the militia.

"The actions are not against (the Mahdi Army). It is the government of Iraq taking responsibility and acting to deal with criminals on the streets," he said.

The target of raids by US and Iraqi forces in Sadr City since Tuesday, he added, have been those firing rockets and mortars into the highly fortified Green Zone, seat of the Iraqi government, and surrounding suburbs.

"Much of the indirect fire... has emanated from east Baghdad and Sadr City," Bergner said, using the term the US military employs for rocket and mortar attacks.

Such projectiles fired on Wednesday wounded three Americans in the Green Zone, US embassy spokeswoman Mirembe Nantongo said.

Residents of Sadr City insisted that Mahdi Army militiamen were the ones being targeted.

Fighters, dressed in their traditional black clothing, were seen on the streets of Sadr City Wednesday, ready to fight the troops.

"Our battle is a battle of solidarity with our brothers in Basra," said Saeed Abbas, head of a small group of Mahdi Army fighters in the neighborhood.

"We are chased by the security forces, we are not attacking them. But when they do attack us we fire back."

Basra has become the theatre of a bitter turf war between the Mahdi Army and two rival Shiite factions -- the powerful Supreme Iraqi Islamic Council (SIIC) of Abdel Aziz al-Hakim and the smaller Fadhila party -- ahead of provincial elections in October.

The three factions are fighting to control the huge oil revenues generated in the province, which is seen as the economic nerve centre of the country.

PHOTO CAPTION 

Iraqi Mahdi Army men take position during clashes in Basra.

AFP