Baghdad, Iraq ? Iraq’s new prime minister announced an agreement Monday by nine political parties to dissolve their militias, integrating some of the 100,000 fighters into the army and police and pensioning off the rest to firm up government control ahead of the transfer of sovereignty.

The plan does not cover the most important militia fighting coalition forces — the al-Mahdi Army of radical cleric Muqtada al-Sadr — or smaller groups that have sprouted across the country since the collapse of Saddam Hussein’s regime in April 2003.

Nevertheless, the announcement by Prime Minister Iyad Allawi is seen as a significant step toward extending the control of the central government that will take power at the end of the month. The agreement, if it works, would also significantly reduce the threat of civil war after the U.S.-led occupation formally ends.

Previous attempts to abolish the militias failed, but the current drive may have a better chance of succeeding because of the reintegration plan for the fighters and the fact that most are controlled by groups that are part of the new government.

“We want to disband the Badr Brigade and to enable its members to join the new Iraqi army and police forces and serve the new Iraq,” said Dr. Haitham al-Husseini, a top official in the Supreme Council for the Islamic Revolution in Iraq, which controls the 15,000-strong Badr Brigade, a Shiite group.

Jassim al-Hilfi, a member of the central committee of the Iraqi Communist Party, said his group was willing to disband its armed components because “we want to be part of the new Iraq.”

Early today, a car bomb exploded at rush hour outside a U.S. base in the city of Baqouba, killing four Iraqis and wounding 12 others, police said. The U.S. military confirmed an explosion, but could provide no further details.

On Monday, roadside bombs killed an American soldier south of Baghdad and wounded three civilians working for a British security firm in the northern city of Mosul, authorities said.

Under the interim constitution adopted in March, armed groups outside government control will be banned as of June 30 when power transfers from the U.S.-run occupation authority to the new interim administration. Coalition officials said the agreement announced Monday makes the ban effective immediately.

Armed militia members roam the mostly empty streets of the Shiite Sadr City district of Baghdad, Iraq. Nine political groups on Monday agreed to disband their militias and transfer some fighters into the new Iraqi army.

Some of the nine militias have effectively dissolved already, and others, notably two Kurdish groups, have been allied with the Americans for years.

The occupation authority had been preparing the plan to abolish militias for months. But the announcement was made by Allawi in what appeared to be a move to enhance his stature.

Al-Sadr’s al-Mahdi Army was excluded because it did not want “to work within the political system, within the political process,” one coalition official said on condition of anonymity.

U.S. officials want to disband the al-Mahdi Army and arrest al-Sadr for the April 2003 slaying of a rival cleric, although authorities have deferred both goals to reduce tensions in the Shiite heartland south of Baghdad. Instead, the coalition has opted to let Allawi, himself a Shiite, and Shiite clerics deal with al-Sadr.