FALLUJAH, Iraq - Gunfire was largely silenced today in the second day of a truce in Fallujah, where Iraqi doctors said 600 people, including many civilians, were killed. The top U.S. military spokesman said about 70 Americans and 700 insurgents had been killed since April 1.

Additional U.S. forces have been maneuvering into place, and the military has warned it will launch an all-out assault on Fallujah if talks there between pro-U.S. Iraqi politicians and city officials - which were continuing today - fall through.

U.S. Brig. Gen. Mark Kimmitt released the first full casualty statistics since widespread fighting erupted on April 4.

"The coalition casualties since April 1 run about 70 personnel. ... The casualty figures we have received from the enemy are somewhere about 10 times that amount, what we've inflicted on the enemy," Kimmitt told a Baghdad press conference.

"In terms of civilian casualties, there is no reliable, authoritative figure out there. We would ask the Ministry of Health, once Iraqi control ... is allowed back in Fallujah, they can get a fair, honest and credible figure and not one that is somehow filtered through some of the local propaganda machines," he said.

Hospital director Rafie al-Issawi said most of the 600 dead in Fallujah were women, children and elderly. But he refused to give their exact numbers, saying that doing so would suggest that the remaining dead - young, military-aged men - were all insurgents, which he said was not the case.

In all, about 880 Iraqis have been killed, according to an AP count, based on statements by Iraqi hospital officials, U.S. military statements and Iraqi police.

The top U.S. commander in Iraq, Lt. Gen. Ricardo Sanchez, acknowledged that a battalion of the Iraqi army refused to fight in Fallujah - a sign of Iraqi discontent with the siege.

Asked about the battalion's refusal on NBC's "Meet The Press" Sunday, Sanchez said, "This one specific instance did in fact uncover some significant challenges in some of the Iraqi security force structures ... We know that it's going to take us a while to stand up reliable forces that can accept responsibility."

Some 900 members of the Iraqi Civil Defense Corps are with three battalions of Marines. U.S. forces on Sunday examined a captured insurgent cache of suicide belts - raising concerns of a deadly new tactic in the city's fighting.

President Bush held out hope for the Fallujah talks, saying the United States was "open to suggestions" on reducing the violence.

Meanwhile, a rash of kidnappings continued. Seven Chinese civilians were abducted by insurgents in central Iraq Sunday evening, China's government said. Today, Beijing urged Iraq's leaders to help free the hostages.

In the last week, militants have kidnapped at least 28 civilians from 11 countries.

Still unknown was the fate of an American hostage, Thomas Hamill, whose captors threatened to kill him unless the Marines withdraw from Fallujah by early Sunday. Other insurgents promised to release three Japanese by Sunday, but the Japanese Embassy in Baghdad said today they had not been freed.

In the south, members of the Iraqi Governing Council have reportedly held talks with followers of radical Shiite cleric Muqtada al-Sadr. His militia raised a bloody revolt last week and still controls three holy cities - Karbala, Kufa and Najaf.

The goal of the separate talks in Fallujah and the south - all conducted by Iraqis, with no Americans participating - was unclear. U.S. commanders demand that control of Iraqi police and U.S.-led coalition forces in the cities be restored and that insurgents in Fallujah lay down their arms and hand over Iraqis who killed and mutilated four American civilians on March 31.

Iraqi Governing Council members, who have harshly criticized the U.S. offensive, are seeking a way to extend the truce and resolve the violence.

U.S. troops retook the city of Kut from al-Sadr followers in the past three days, in the first major foray in months by the American military into southern Iraq. But military action to retake the other cities could require fighting near some of Shiite Islam's holiest shrines, raising the possibility of inflaming Shiite anger at the U.S.-led occupation.

In Fallujah, hardly a shot was heard this morning, more than 36 hours after insurgents in the city said they were calling a cease-fire. The Marines have halted offensive operations since Friday.

Despite the truce, guerrillas overnight made sporadic attacks, said Lt. Col. Brennan Byrne. Marines killed two insurgents setting up a machine gun near a patrol and others were fired on by gunmen hiding in a school, he said.

Byrne said U.S. Marines would not withdraw from their positions in Fallujah. "Diplomacy is just talk unless you have a credible force to back it up," he said. "People will bend to our will if they are afraid of us."

Marines on Sunday investigated a bomb-making factory first uncovered three days earlier. Along with five suicide belts found in the initial raid, they uncovered U.S. military uniforms - suggesting suicide bombers may try to use them to get close to American forces, Byrne said.