BAGHDAD, Iraq --At least 20 gunmen and eight civilians were killed when the Iraqi army battled fiercely for hours yesterday with members of a militia loyal to Muqtada al-Sadr, the radical Shiite cleric, in the southern city of Diwaniyah, Iraqi officials said.
The violence, which one Iraqi general said included militiamen executing Iraqi soldiers in a public square, amounted to the most brazen clashes in recent memory between Iraqi government forces and al-Sadr's militia.
After weeks of rising tensions and skirmishes between elements of the militia and U.S.-led forces, it could increase pressure on Prime Minister Nuri Kamal al-Maliki, a conservative Shiite, to find a way, whether political or military or both, to quickly rein in al-Sadr's powerful militia.
The battle erupted after a particularly violent weekend in Iraq for both U.S. soldiers and Iraqi civilians, in what had been a relatively quiet month.
The U.S. military announced yesterday the deaths of nine American service members in attacks Sunday. In Baghdad, a car bomb killed at least 13 people yesterday and wounded dozens at a checkpoint just outside the Interior Ministry headquarters.
With sectarian violence soaring, U.S. generals and the U.S. ambassador, Zalmay Khalilzad, say that militias are now the single greatest threat to the stability of Iraq and that the Iraqi government must move urgently to disband them.
But al-Maliki has yet to introduce any new policy and has refrained from strong condemnations of al-Sadr's militia, the Mahdi Army. Al-Maliki relies on al-Sadr, who is enormously popular among poor Shiites, for political support against rival Shiite politicians. Al-Sadr controls at least 30 seats in the Parliament and several ministries, and he maintains close ties to al-Maliki's political group, the Islamic Dawa Party.
Earlier this month, after the Americans called in air support during a raid with Iraqi forces in an al-Sadr stronghold in Baghdad, al-Maliki denounced the move by the Americans and said he had never given permission for it.
But the fighting yesterday in Diwaniyah underscored the recalcitrant, rebellious nature of the Mahdi Army and raised the specter of the two uprisings that al-Sadr led against the Americans and the Iraqi government in 2004.
After several hours of gunfire and mortar rounds, "the clashes reached a point where members of the militias executed soldiers after their ammunition ran out in a public square, in front of residents," said Maj. Gen. Othman al-Ghanimi, commander of the 8th Division of the Iraqi army in Diwaniyah. "This is true terrorism and a crime." The Mahdi Army denied the reports of executions.
The fighting ended only after Shiite politicians visited al-Sadr's office in the holy city of Najaf to negotiate a cease-fire.
Al-Ghanimi and other Iraqi army and police officials said several militias were involved, not just the Mahdi Army. But they said the seed of yesterday's violence was planted a week ago, when a roadside bomb they believe was planted by the Mahdi Army, with a senior officer of the 8th Division as its target, killed at least two Iraqi soldiers. Two days later, the Iraqi army arrested a member of the Mahdi Army and began an operation against the militia.
The surge in violence, with more than 100 people killed Sunday and yesterday, comes as Iraqi, U.S. and British officials continue to assert that a civil war here can be averted.
In fact, Maj. Gen. William B. Caldwell IV, the lead spokesman for the U.S. military, said yesterday that attacks and killings in Baghdad had declined this month thanks to the deployment of about 12,000 additional U.S. and Iraqi troops. He said several neighborhoods that had been searched over the past few weeks under a new security plan were reviving, with stores reopening and children riding bicycles in the streets.
Yet al-Sadr and his Mahdi Army have remained an operational blind spot. Al-Maliki, a Shiite who depends on support from al-Sadr's allies in Parliament, has not confronted al-Sadr publicly. Sadr City, a Mahdi bastion, has not been searched or raided in a thorough manner even though it is one of the capital's most violent areas. The Americans have maintained some distance; even as the fighting raged in Diwaniyah yesterday, Caldwell told reporters he had not been briefed on the battle and could not comment.
Of the nine U.S. soldiers killed Sunday, four died after their armored Stryker unit was ambushed by a bomb and gunfire in Ghazaliyah, a western Baghdad neighborhood that had been described as a model of improved security since American and Iraqi forces had strengthened their presence there. Three of the U.S. soldiers were killed in two roadside bomb attacks, and one was struck by small-arms fire in or near Baghdad. One was killed in Anbar province.