Updated

A U.S. general called on Sunni militants in Fallujah (search) on Saturday to join a bilateral cease-fire. Insurgents struck U.S troops in Baghdad (search) and central Iraq, setting a tank on fire in the capital and engaging in battles that killed 40 Iraqis, a U.S. spokesman said.

Sunni insurgents did not immediately respond to the general's call for Fallujah, where bloody fighting has been raging all week, but a team of Iraqi leaders entered the city to hold talks with local leaders. Marine commanders said they had no orders yet for a full cease-fire.

Explosions and sporadic gunfire were heard Saturday afternoon, and Marines largely remained in the industrial zone they hold in the eastern part of the city, 35 miles west of Baghdad.

Some Marines moved a few blocks into a nearby neighborhood, breaking into homes, witnesses said, in an apparent attempt to clear out gunmen firing on them.

"Today what we are seeking is a bilateral cease-fire on the battlefield so we can allow for discussions (in Fallujah)," Brig. Gen. Mark Kimmitt told reporters in Baghdad. "This is an aspiration."

He added that he was "hoping to get this message to the enemy through this press conference" and the Arabic press.

In Baqouba, northeast of the capital, gunmen attacked government buildings and police stations, fighting U.S. troops in battles that killed around 40 Iraqis and wounded several Americans, said Capt. Issam Bornales, spokesman for the 1st Infantry Division's 3rd Brigade.

Insurgents also fought U.S. troops in Baghdad's northern, mainly Sunni neighborhood of al-Azamiyah.

Guerrillas attacked a tank on a highway near the airport in western Baghdad on Saturday, setting it on fire. Also in the west of the city, a convoy of supply trucks being escorted by two U.S. Humvees was attacked. One of the trucks was set ablaze and the driver kidnapped, said Majid Hameed, a witness. The kidnapping could be confirmed and the driver's nationality was not known.

Along with violence in central and southern Iraq this week, there has been a rash of kidnappings by militants, including of foreign civilians. Militants holding three Japanese have threatened to burn them alive unless Tokyo withdraws its troops from Iraq by Sunday, a demand Japan has rejected.

While violence continued in central Iraq on Saturday, there was relative quiet in the south — where the militia of radical Shiite cleric Muqtada al-Sadr (search) has waged an uprising against coalition forces, seizing several cities.

Leaders of al-Sadr's militia said Saturday that they would not launch attacks on U.S.-led coalition forces in Karbala, 65 miles south of Baghdad, until the end of a religious festival this weekend.

Hundreds of thousands of pilgrims are in Karbala and other Shiite cities to mark al-Arbaeen, the end of the mourning period for a 7th-century martyred Shiite saint. Ceremonies are to be held until Sunday night.

"We decided to halt the military activities until the end of al-Arbaeen," said Khudeir al-Ansari, head of al-Sadr's office in Karbala, home to the Imam Hussein Shrine at the center of the ceremonies.

U.S. commanders also have suggested they will hold off on trying to uproot al-Sadr's militia from Karbala and nearby Najaf and Kufa until after the al-Arbaeen ceremonies.

In their first major military move into south in months, around 1,000 U.S. troops backed by tanks swept into the city of Kut on Wednesday to push out al-Sadr militiamen who had seized control. Kimmitt said al-Sadr followers were driven from much of Kut in the initial assault, and he expected the rest of the city to be under U.S. control soon.

In Fallujah, a party of 35 Iraqi officials — including several Governing Council members — entered the besieged city Saturday to hold talks with local leaders. Council members have expressed increasing anger over the U.S. siege, calling it a "mass punishment" for 200,000 residents.

The purpose of the talks was unclear. Kimmitt underlined that the talks were going on with city officials who "want to see Iraqi police back in the police stations, that want to see Iraqi Civil Defense Corps members walking the streets of Fallujah, that want to see the Iraqi army walking the streets of Fallujah. Not terrorists, not extremists, not foreign fighters."

A Marine commander said he had no orders yet for a full cease-fire.

"I've got no direction of any kind on a cease-fire, so I will continue to fight until I'm instructed to do different," said Lt. Col. Brennan Byrne, commander of the 1st Battalion, 5th Marine Regiment.

Italian Prime Minister Silvio Berlusconi, meanwhile, made a surprise visit to Italian troops in the southern city of Nasiriyah, which saw fighting with al-Sadr followers earlier in the week but has largely calmed since.

Despite heavy fighting since Monday morning, Marines have insisted they were winning the battle to uproot Sunni insurgents in Fallujah.

When ordered on Friday to halt all offensive operations, Marines complained that doing so would expose them to insurgent attacks. So they demanded and received the right to conduct offensive operations necessary to prevent attacks on their positions — a more aggressive stance than only responding to attacks.

The Marines have been in position encircling Fallujah and in a large industrial zone inside the southeastern part of the city.

During Friday's unilateral halt began, they did not advance into residential area to engage gunmen there. But one Marine was killed Friday and another wounded in exchanges of fire.

The death — along with those of three Marines a day earlier announced Friday — brought the toll of U.S. troops killed across Iraq this week to 46. The fighting has killed more than 460 Iraqis — including more than 280 in Fallujah, a hospital official said. At least 647 U.S. soldiers have died in Iraq since the war began in March 2003.

During Friday's pause, a stream of cars headed out of the city, carrying families trying to escape the violence. Marines allowed women, children and the elder to leave, but turned back men.

Fallujah residents emerged from their homes for the first time in days Friday, with many burying their dead in the city's football stadium since cemeteries on the city's edge could not be reached.

Abdul-Karim Mahoud al-Mohammedawi, a Shiite on the Governing Council, announced he was suspending his council seat until "the bleeding stops in all Iraq." He also met Friday with al-Sadr, whom U.S. commanders have vowed to capture.

A Sunni council member, Ghazi al-Yawer, said he would quit if the Fallujah talks fell through.