BAGHDAD, Iraq, Nov. 19 - The drive was supposed to take no more than 15 minutes, a quick dash across a few rubble-strewn blocks of Falluja to spirit Sahar Muhammad Abdullah, 23, and her family to safety in a house near a mosque.

But hundreds of feet short of their destination, the family stumbled into a company of marines who had transformed the mosque into a temporary fortress, with snipers and machine gunners perched on the roof. They spotted the gray car carrying the family, inching along.

A barrage of bullets followed. Minutes later, Ms. Abdullah's mother lay bloodied and dying in the rear seat, glass shards strewn about her. Ms. Abdullah, hit in the back by a bullet, collapsed into her mother's lap. Three men in the car were lightly wounded.

The family's journey ended there, and a much longer one began.

"There are days when I can't sleep at all," Ms. Abdullah said from a hospital bed in Baghdad. "I keep thinking of what happened to us." Her family has not yet told her that her mother is dead.

Ms. Abdullah spent two hours telling her tale, all the time wincing in pain. Dressed in a burgundy robe, she leaned over the bed occasionally to sip water through a straw. A cousin and an aunt who had fled Falluja weeks earlier tended to her, dabbing at her tears with tissues.

What befell Ms. Abdullah and her family on Nov. 12 is just one incident in which civilians were reported wounded or killed during the week-long Falluja offensive. While no neutral group has been able to enter the city to count casualties, officials of the International Red Cross in Baghdad estimate that as many as 800 civilians may have died.

Lt. Gen. John F. Sattler, commander of the First Marine Expeditionary Force, said Thursday that he did not know of any civilian deaths.

The marines at the mosque, from Company B, First Battalion, Eighth Marines, had spent the morning of Nov. 12 fending off insurgent attacks, and they were operating under rules of engagement that said "unauthorized movement of civilian vehicles towards Marines may pose" a suicide bomb threat. The same rules tell marines to "spare civilians and civilian property, if possible."

Ms. Abdullah's family was not aware that American troops had stormed the Abdul Aziz Mosque, just blocks from their home in the Nazal neighborhood, and that battles were raging all around, she said.

They had hunkered down when American armor first rolled into Falluja on Nov. 8. They decided to wait out the invasion, she said, because the family had survived the aborted offensive last April. This assault would be no worse, they thought.

Ms. Abdullah's father died years ago. Her brother was arrested by the Americans this year, she said, because he happened to be near the site of a roadside bomb explosion. That left Ms. Abdullah and her mother, Khaluda Ismail Khalif.

Three men were staying at their home to guard against looters. They were Ms. Abdullah's uncle, Abdullah Ismail Khalif; his son, Alaa Muhammad; and a young neighbor, Muhammad Abdul Latif. As airstrikes pounded the city, the five huddled together to read from the Koran.

"We tried to calm each other and we tried to accept what God had in store for us," Ms. Abdullah said. "We'd beseech God to keep Falluja safe, to shield it from the bombings."

Electricity and water had been cut off. But the family had stored water and squirreled away some basic rations to cook at sunset each day to break the Ramadan fast.

"We prepared the food, but no one could eat, because of our dark spirits," Ms. Abdullah said.

Mujahedeen with Kalashnikov rifles and rocket-propelled grenades darted from building to building. The explosions got louder and heavier by the day. One bomb destroyed the minaret of the Abdul Aziz Mosque, and another pulverized a neighboring house, shattering the windows in Ms. Abdullah's home.

"We were used to the bombing," Ms. Abdullah said. "But then we thought, 'If we're injured, who would treat us?' So we decided to move to a place where people could attend to us if that happened."

That meant driving to the house of Mr. Khalif, a few blocks away.

The family knew the Iraqi government had imposed a curfew on the city. Anyone moving in the streets could be shot. But they saw only mujahedeen outside, not Americans. Besides, "we thought if we get hit, we'll be martyrs," Ms. Abdullah said.

On Nov. 12, at 2:30 p.m., the five packed clothes and bags of food and piled into the car. The uncle drove. The neighbor, Mr. Latif, rode in the passenger seat holding a white towel out the window, Ms. Abdullah said. Gunfire rattled nearby, then died down.

"We had no idea what had happened to the blocks of houses next to us," Ms. Abdullah said. "We thought, 'We've never seen anything like this.' The car could barely move because of the debris in the streets."

They rounded a corner by the mosque and saw the marines for the first time, crouching atop the roof, their guns pointed outward. Tanks had rammed through the mosque compound's outer wall, leaving large holes.

Mr. Khalif veered onto the street where he lived. The marines opened fire, Ms. Abdullah said. "I fell into my mother's lap and started screaming," she said.

The two younger men, barely injured, dashed into houses on either side of the street. Mr. Khalif stumbled from the driver's seat, the left side of his robe drenched in blood. He walked toward the mosque holding up the white towel.

Inside the main prayer room, word spread among the weary marines that some of their unit had just shot civilians. They had spent the morning repelling guerrilla assaults after seizing the mosque at dawn. Several marines and Iraqi soldiers raced out to check on the casualties, accompanied by a reporter and photographer for The New York Times.

"Don't shoot, don't shoot!" Mr. Khalif yelled in Arabic. "I have a family with me. There are women in the car."

"Just shoot him," two Iraqi soldiers said.

The Americans held off, and Mr. Khalif popped back around the corner. The troops walked toward him with an M-1 Abrams tank advancing in front. From the south, guerrillas fired a few rounds at them with Kalashnikovs and rocket-propelled grenades, then disappeared.

Ms. Abdullah's cousin and the neighbor emerged from hiding, their arms held high. The Iraqi soldiers shoved them to the ground and called them dogs, Ms. Abdullah said. An insurgent with a machine gun lay sprawled near the car, the top of his head blown off; it was unclear when he had been killed.

An Iraqi interpreter pulled Ms. Abdullah from the back seat.

"I told them, 'I want you to take out my mother, even if she's dead,' " she said.

A Marine lieutenant looked into the car and said the mother was no longer breathing. No one translated that. The troops led the others into the caretaker's room in the ruined mosque, where medics treated them.

They tried to remove the bullet from Ms. Abdullah's back without taking off her clothes.

"I forgot all my pain when I saw the condition of the mosque," Ms. Abdullah said. "I saw the Americans sitting on boxes full of Korans, and at that moment I wanted to grab one of them and kill him. I would have preferred to stay in the car bleeding rather than witness that scene."

"The Americans may have been sympathetic to me," she said, "but they slaughtered other people."

The marines took the wounded to a hospital outside Falluja, and ambulances brought them to Baghdad.

Mr. Khalif and his son have since recovered and departed for a village near Falluja to check on relatives, Ms. Abdullah said. She plans to stay with an aunt in Baghdad when she gets better.

As she finished telling her story, she turned her head toward the window and stared out across the city to the Tigris River, the air hazy in the fading afternoon light.

"I dream of my mother every night," she said. "We were at our home. But she wasn't O.K. She was pale, and there was nothing left of her."

Dexter Filkins and Ashley Gilbertson contributed reporting from Falluja for this article.