Diwaniyah, Iraq ? Shiite militiamen battled Iraqi forces for 12 hours Monday, leaving at least 40 people dead and underlining the government’s struggle to rein in an anti-U.S. cleric. The U.S. announced nine soldiers killed over the weekend in separate fighting.

The fighting in this southern city dominated a day that saw at least 19 people die in two suicide car bombings in Baghdad – one outside the Interior Ministry and one on a line of cars waiting for fuel at a gas station.

Diwaniyah, 80 miles south of Baghdad, is a Shiite-dominated city where the influence of firebrand cleric Muqtada al-Sadr’s Mahdi Army has been gradually increasing. The militia already runs a virtual parallel government in Sadr City, a slum in eastern Baghdad.

But the government of Prime Minister Nouri al-Maliki, a Shiite, has found it difficult to control al-Sadr, whose movement holds 30 of the 275 seats in parliament and five Cabinet posts, and his forces. Al-Sadr’s backing also helped al-Maliki win the top job during painstaking negotiations within the Shiite alliance that led to the ouster of Prime Minister Ibrahim al-Jaafari.

Many Sunnis have expressed disappointment that al-Maliki’s government has not moved to curb Shiite militias, especially the Mahdi Army, which have been blamed for much of the sectarian violence that has followed the Feb. 22 bombing of a Shiite mosque in Samarra.

A prominent hard-line Iraqi Sunni cleric, Harith al-Dhari, said Friday he was willing to meet with top Shiite religious leaders, part of an initiative to curb sectarian violence – but also to press Shiite leaders into a response.

Residents of Diwaniyah, Iraq, 80 miles south of Baghdad, flee the city after gunbattles erupted between Iraqi forces and militiamen of the Mahdi Army loyal to radical cleric Muqtada al-Sadr. By Monday evening, control of the city was split between government troops and militia members.

American forces also have been wary of confronting the militia, because of al-Sadr’s clout over the government and his large following among majority Shiites. Al-Sadr mounted two major uprisings against the American-led coalition in 2004 when U.S. authorities closed his newspaper and pushed an Iraqi judge into issuing an arrest warrant against him.

The clashes in Diwaniyah began Saturday night after a rocket attack on a Polish-run base earlier in the day, then resumed Sunday night, said Lt. Col. Dariusz Kacperczyk, a Polish military spokesman.

Sheikh Abdul-Razaq al-Nidawi, the manager of al-Sadr’s office in Diwaniyah, told The Associated Press that trouble had been brewing since Saturday night when the Iraqi army arrested an al-Sadr supporter from the Jumhouri neighborhood.

On Sunday, the army raided the same place and “a gunfight erupted between them and the Mahdi Army,” al-Nidawi said.

Army Capt. Fatik Aied said gunbattles broke out about 11 p.m. Sunday south of Diwaniyah, when Iraqi soldiers conducted raids in three neighborhoods to flush out militiamen and seize weapons.

Al-Nidawi said “a big force of the army raided Jumhouri, Sadr and Askouri neighborhoods and clashes broke out (again) between the army and the Mahdi Army.” He said the raids took place early Monday.

Fighting continued for most of the day, as the army brought in extra troops from other cities to reinforce its soldiers, said Brig. Gen. Othman al-Farhoud, commander of the 8th Iraqi Army Division.

By evening, the militia had set up road checkpoints and taken over seven neighborhoods in the south and east of the city, while the Iraqi army was controlling the northern and western parts, Aied said.