A force of nearly 3,000 U.S. and Iraqi troops opened a new offensive against insurgents in a wide area south of Baghdad that has become notorious for its lawlessness, U.S. military officials announced today.

The troops, led by the 24th Marine Expeditionary Unit, were sweeping through the central Iraqi province of Northern Babil, military officials said in a brief statement. The troops also took control of the Jurf Kas Sukr Bridge southwest of Baghdad, a critical crossing point on the Euphrates that U.S. officials said is used by insurgents moving to Baghdad and Fallujah.

At least 30 insurgents were captured in the initial fighting. The region being targeted runs from Baghdad to the city of Hilla in the south and west to Karbala, roughly 600 square miles.

The campaign comes after U.S. and Iraqi troops moved last week to subdue militants in Samarra and restore government control to that area. Insurgents took that city, about 35 miles north of the capital, last summer when the police force fell apart.

Iraqi and U.S. officials have said that the incursion into Samarra was the beginning of efforts to restore order again in a number of area that have fallen into the hands of insurgents. Part of the push comes from officials' concerns that the national election in January will be marred if voting cannot take place in large sections of the country.

"This is the first step in operations to take back lawless areas," Interior Minister Falah Naqib, told reporters Saturday. "The Iraqi government is moving from a defense position to an offensive position to regain control over all of Iraq."

Defense Secretary Donald H. Rumsfeld reiterated that yesterday in a speech at the Council of Foreign Relations in New York, saying the Samarra offensive is a model for other actions that U.S. forces will undertake.

Earlier in the day, Iraqi interim Prime Minister Ayad Allawi said that he has been talking with representatives of maverick Shiite Muslim cleric Moqtada Sadr and had brokered an accord to end fighting in a vast area of eastern Baghdad that serves as a redoubt for fighters loyal to Sadr.

"Fortunately, there are positive signs in some areas. I met with some brothers in Sadr City and we laid the basis for an agreement to end all their armed manifestations and to give up all their arms," Allawi told the National Council, a watchdog over his interim government, the Associated Press reported.

The Sadr City neighborhood is frequently the site of violence and anti-American sentiment.

U.S. forces battled rebels overnight in Sadr City. U.S. AC-130 warplanes opened fire on rebel targets there after a patrol came under attack late Monday, U.S. officials said. They said the planes targeted insurgent machine gun crews on the ground.

Hospital officials in Sadr City said at least one Iraqi was killed and two were injured when their car came under fire during the fighting, news agencies reported. Explosions reverberated through the slum until dawn, residents said.

Iraqi insurgents killed an American soldier with a roadside bomb near Baghdad, Iraqi and U.S. authorities reported today. The soldier was from the Army's 13th Corps Support Command and two others were wounded. No other details of the incident were immediately provided.

In Mosul, a parked car packed with explosives blew up as a U.S. convoy was driving by, prompting U.S. soldiers to open fire, news agencies reported. At least three Iraqis in a passing vehicle were killed and a number of others were injured, Iraqi police said, according to the Associated Press. There was no immediate word on U.S. casualties in the car bombing.

In Mosul and the outskirts of two other northern cities, police in the past two days have found the decapitated bodies of five Iraqi men -- apparently the latest victims of insurgent violence aimed at denying support for Iraq's interim government and the U.S. military.

Three decapitated bodies have been found in and around Mosul, two of them dumped separately today in the central part of the city. Two of the bodies were identified as those of Iraqis. The third victim, although not yet identified, is also believed to be an Iraqi, Reuters reported.

Elsewhere, the corpse and head of a former Iraqi army officer who worked at a U.S. military base in the northern city of Kirkuk were found southwest of the city, and the headless body of an Iraqi who worked at a U.S. barracks near Baiji was found Monday night.

Another decapitated corpse that appeared to be that of a Westerner has turned up south of Baghdad, the AP reported.

An insurgent group headed by Jordanian terrorist Abu Musab Zarqawi has beheaded at least three American civilians in Iraq, and about two dozen other foreigners have been killed after being abducted. Now, beheadings appear to be growing more common in cases in which Iraqis are kidnapped, some of them apparently targeted for working with foreign troops or contractors.

Officials also reported that 10 Iraqi police officers were killed Monday in two attacks south of Baghdad that appeared to be in the area of the latest U.S. incursion. It was not clear if there was any link.

In the first of the two attacks reported, Brig. Ali Musaw told the Associated Press that insurgents opened fire on police officers returning to the city from Mahmudiyah, which is 15 miles south of the capital. Seven officers, including Lt. Col. Abdul-Latif Metasher Nejm, were killed.

Another attack a bit further south, also on Monday, resulted in three police being shot dead at a gas station, policeman Faez Nasser told the AP. One survivor told investigators that the assailants took $1 million from the police officers' vehicle. It was unclear why they were carrying such a large amount of money.

In Baghdad, several mortar rounds fired by unknown attackers landed near Iraqi government offices today. One civilian was killed and another wounded by the shelling near an Interior Ministry passport office, the Reuters news agency reported. At least one round also landed near the Oil Ministry.

In Ramadi, 70 miles west of Baghdad, U.S. Marines opened fire on three masked men who were seen planting a roadside bomb Monday, killing two and wounding the third, a Marine spokesman said. A civilian woman and child were also injured in the initial exchange of fire, but it was unclear how their injuries occurred, the spokesman said.

In another incident in Ramadi, a car bomb that exploded near a U.S. convoy today killed two civilians and wounded at least four others without damaging the convoy, Reuters reported.

In an effort to demonstrate goodwill following heavy fighting in the holy city of Najaf in August, the 11th Marine Expeditionary Unit announced new payments of condolence and damage-repair money to Iraqi families that lost loved ones or property in the crossfire between U.S.-led forces and members of Sadr's Mahdi Army militia.

The latest payments of $200,300 brought the total paid out since Sept. 20 to $367,300, a Marine statement said.