Baghdad, Iraq ? Shiite militiamen loyal to radical cleric Muqtada al-Sadr agreed Saturday to begin handing in weapons, a significant step toward restoring order in Baghdad’s sprawling Sadr City slum as the interim government struggles to curb Iraq’s more widespread Sunni insurgency.

In a sign of persistent Sunni unrest, clashes flared in several cities as the search continued for the body of British hostage Kenneth Bigley, who was decapitated by his abductors — reportedly after a failed escape attempt. Sporadic explosions could be heard late Saturday near the Tigris river around an area where U.S. troops and Sunni insurgents have clashed.

Interim Prime Minister Ayad Allawi’s government hopes to quiet insurgent enclaves before legislative elections planned for January. U.S. and Iraqi officials have been negotiating for weeks with tribal and religious leaders in key rebel strongholds but have said they are prepared to use force if talks fail, as they did in Samarra last month.

Ali Smeisem, a senior aide to al-Sadr, said the Mahdi Army militia would begin turning in medium and heavy weapons at three Baghdad police stations Monday in an operation expected to last five days.

As a confidence-building measure, the government will suspend raids on al-Sadr’s followers in the capital’s northeastern Sadr City district, site of weeks of clashes with U.S. and Iraqi forces, Smeisem said.

The minister in charge of national security, Qassem Dawoud, said the government was pleased with the agreement, “which aims at sparing Iraqi blood, supporting sovereign law and the peace process in Iraq.”