On one side of the concertina wire lining an avenue stood 100 U.S. troops, five Bradley Fighting Vehicles and two M1-A1 Abrams tanks. Across the street were about 1,000 men, women and children of this embattled northwestern city.

The military had warned in leaflets dropped by helicopter and messages played over loudspeaker Tuesday morning that it would soon raid the insurgent-controlled neighborhood of Sarai, east of the city center, and asked civilians to evacuate through checkpoints in the southern part of town. But the Sarai residents, most of them Sunni Turkmens, insisted they would either flee northward or remain in their homes, come what may.

After an eight-hour standoff marked by a cycle of negotiation, miscommunication, occasional gunfire and flashes of anger, one family, about 17 people, agreed to leave the city with a military escort, after a U.S. commander gave the crowd "one final chance." The rest retreated into Sarai, vowing to take their chances.

"A lot of people are just barricading themselves in, which is a big mistake," said Staff Sgt. George Kakeletris, a psychological operations soldier who drove a Humvee all day up and down the avenue, which the military calls Bel Air, blaring messages in Arabic from speakers mounted on the roof.

About 5,000 U.S. and Iraqi soldiers entered Tall Afar four days ago in an offensive aimed at dislodging insurgents. Fighting has been sporadic so far. One U.S. soldier has been killed, along with at least 200 suspected insurgents, said Col. H.R. McMaster, commander of the 3rd Armored Cavalry Regiment, which is leading the assault.

Five civilians were killed Tuesday when a suicide bomb detonated near an Iraqi army checkpoint. Four days of small-scale raids and house-to-house searches have allowed troops to encircle Sarai, where commanders here believe insurgents have massed.

The Iraqi government has asked the military commanders to minimize civilian casualties in this highly volatile region. A U.S.-led invasion of Tall Afar one year ago this month outraged the Turkish government, which argued that the assault victimized Turkmens, who share ethnic ties with Turks. When the U.S. withdrew, insurgents returned, capitalizing on anger over the offensive to consolidate control over the city, which has also been marred by sectarian violence between Sunni and Shiite tribes.

"Steps are being taken to ensure that this is done with the least possible amount of harm done to civilians," McMaster said.

But several Sarai residents said they had been warned that Shiite residents or policemen, who are concentrated in southern Tall Afar, would attack if they left in that direction.

"I would rather die from American bombs in my home with my family than walk south," a man in a gray dishdasha, or robe, and white head scarf explained to soldiers. "People are saying the Shiites will kill you or kidnap you. That is a disgrace."

The evacuation of Sarai, the oldest section of Tall Afar and a web of narrow streets where fighting is expected to be difficult, was supposed to help prevent civilians from being hurt or killed during the offensive's final phase. The military strung nearly a mile of concertina wire along Bel Air, on the northern edge of the neighborhood, on Sunday to encourage people to migrate south, where it had established checkpoints to prevent insurgents from fleeing undetected. Among 200 people who followed instructions and fled south Tuesday, soldiers discovered a man suspected of being an insurgent who was dressed as a woman, complete with prosthetic breasts.

For the military, problems began at 8 a.m. Tuesday when soldiers who had spent the night in an abandoned house awoke to about 300 Sarai residents who had picked their way across the wire and were sitting in the street outside the house, asking how they could get out of Tall Afar.

The soldiers escorted the crowd back to the other side of the wire but found that at least 500 other people were waiting to come across. To block them, they placed tanks and Bradleys along Bel Air and sent soldiers with rifles to the roofs overlooking the street.

Men who identified themselves as tribal leaders of the people attempting to flee would periodically walk across the street -- which is pockmarked with dozens of craters caused by explosions -- stepping gingerly over the wire to negotiate with soldiers. Some residents said that their relatives were too sick or frail to travel south of the city or that their tribe was located in the north so they needed to go in that direction. Others said they actually lived outside Sarai but had spent the night in the neighborhood and were trapped by the concertina wire. The soldiers refused to let them pass.

"I am sure 99 percent of you are good people who are telling us the truth," Capt. Alan Blackburn, commander of the 3rd Armored Cavalry Regiment's Eagle Troop, 2nd Squadron, which was policing the area around Bel Air, told one of the men who wanted to go north. "But I am sure that there are a few people in that crowd who are not good people. And we don't have the facilities here to check them. You have to go south."

"I am not going unless you drive me in a tank," the man said. "There are no bad people in Sarai. If you come with me, I will take you to all the houses and you can see. The bad people are the Shiites in the south."

Late in the afternoon, the soldiers relented and offered a compromise. They told the residents they could exit to the north if they agreed to board military trucks bound for a base just outside the city where they could be processed and then released if they proved not to have ties to the insurgency.

"It sounds like a trick to take us south to the Shiites," one man said.

"We will go only if we can drive our own vehicles," another countered.

About 3 p.m., Lt. Col. Christopher Hickey, the Squadron commander, arrived to make a final plea. "I am trying to help you to get out of a very dangerous situation. You are going to be in danger if you stay here, I am telling you," he said. "Please, this is your last chance."

As he turned away from the crowd, one family emerged, with nine adults carrying baggage and eight children in tow. "Anyone else?" Hickey asked, beckoning. "Okay, then we will save these people," he said, and walked away.

Residents flee to a camp outside Tall Afar, which was seized by insurgents and is now the site of a joint U.S.-Iraqi operation.