Followers of a radical Shiite Muslim cleric began handing in weapons in a Baghdad slum today under a deal with the Iraqi interim government, as clashes and bombings continued elsewhere, killing at least two U.S. soldiers and two Iraqis.

With U.S. troops watching from a distance, fighters of the Mahdi Army militia loyal to Moqtada Sadr brought medium and heavy weapons to three Iraqi police stations in Sadr City, a militia stronghold in northeastern Baghdad, at the start of a five-day process aimed at handing security responsibility for the sprawling district to Iraqi government forces.

It was not immediately clear, however, whether the weapons being surrendered would be sufficient to eliminate the Mahdi Army as a competing security force. While agreeing to turn in weapons, Sadr has stopped short of pledging to disband his militia, which has battled U.S. and Iraqi forces in the holy city of Najaf and other Shiite strongholds.

Under the deal, fighters are supposed to be paid for turning in weapons, with rates ranging from $5 for a hand grenade to $1,000 for a heavy-caliber machine gun.

At the Nasr police station in Sadr City, an Iraqi police major said fighters this morning turned in machine guns, TNT paste, land mines and other explosives, the Associated Press reported. But since the officials responsible for handing out the payments had not shown up, the fighters instead got receipts. One of the fighters who trooped to the station brought in two grenade launchers.

At another police station where guns and explosives were spread out on the ground, a pickup truck arrived with 20 grenade launchers and dozens of mortar rounds, AP reported.

In addition to the payments, the Iraqi government agreed in return for the weapons to suspend raids in Sadr City and promised to start releasing Sadr followers who had not committed crimes.

Ibrahim Jafari, the interim vice president, hailed the program as a "good and positive initiative" that he hoped would be followed in other insurgent enclaves, AP Television News reported.

U.S. troops, along with Iraqi security forces, have been battling Sadr's Mahdi Army for months, pounding Sadr City from the ground and air on a regular basis.

While large numbers of Sadr fighters have reportedly been killed, the military effort has not suppressed the insurgency.

Today is the first of five days during which militia members are to surrender their weapons in exchange for cash payments. Iraqi security forces then will be free to search suspect houses.

"We are trying to concentrate on the concept of the rule of law, disarming all of the illegal militias and arresting all of the terrorists," Qasim Daoud, Iraq's national security adviser, said. "These concepts are paramount in our minds."

In some of the latest violence, two American soldiers were killed and five injured today in a rocket attack in southern Baghdad, the U.S. military said. A brief statement on the incident said the rockets struck at about 8 a.m. but gave no other information and did not indicate who might have been responsible.

The deaths brought to at least five the number of American troops killed since Friday.

Two car bombs in Baghdad killed at least 11 people Sunday, including one American soldier. The U.S. military also announced the death of a Marine in Anbar province on Saturday, when a car bomb exploded beside a Marine convoy outside the city of Fallujah.

A fifth soldier was killed Friday when his patrol was attacked near the town of Tuz, about 100 miles from Baghdad.

Separately today, news agencies reported that a suicide car bomber attacked a U.S. military convoy in the northern Iraqi city of Mosul, killing two Iraqis and wounding 18 other people.

"Initial reports indicate that there were civilian and military casualties," the U.S. military said in a statement, adding that it had been a "complex" attack.

Insurgents have frequently mounted attacks on U.S. forces in Mosul, 240 miles north of Baghdad.

Also in Mosul, police said the beheaded bodies of two residents had been found in the city in the past 24 hours. One was discovered today in an eastern district, the other in the south of the city the previous day.