But if the eye was quiet, around it a storm raged. In the procession that had brought the coffins to the graveyard, and in the parking lot nearby, angry men fired AK-47's into the air in competitive bursts of outrage. One rode a bicycle, steering with one hand, shooting with the other.

They vowed revenge for the deaths of the five men, who were among as many as nine — including the imam — who local people said were killed Monday night in an explosion at a mosque here, 35 miles west of Baghdad. 

They said an American aircraft had fired a missile into the building, reducing two rooms to rubble and killing the men, who had gathered for Koranic study inside. The explosion came before another day of violence in Iraq, in which six American soldiers were wounded in two separate attacks. [Page A16.]

In truth, according to American military officials, some witnesses and neighbors, the available evidence seems to suggest that the explosion had come from within the mosque, perhaps as a result of explosives being stored — or prepared for use — there.

But to the seething men, evidence mattered little. "If each day we've been hitting two tanks," a man who would not give his name said of the persistent anticoalition attacks here over the past several weeks, "we're going to start hitting six tanks each day."

"There's no use talking to journalists," a man in a pickup truck pulled up to shout, as his passenger cocked his weapon and fired into the air. "If anyone's carrying a gun, they should go for jihad."

The reaction to the blast showed that American troops are being held responsible for every violent act that happens here as they try to maintain control and protect themselves, no matter who actually did it.

This town, heavily Sunni Muslim and a stronghold of support for Saddam Hussein, has been a center of resistance to the American-led occupation, with regular attacks on American troops and vehicles.

In April, American soldiers shot and killed 15 protesters here, souring an already tense relationship.

Whatever happened Monday night, it is certain to make things worse.

Everyone agrees that at around 11 p.m. an explosion reduced two rooms of the Al-Hassan Mosque to rubble. Khalida Gadha, 35, ran out from her house across the street and saw a scene of scattered bodies and body parts so revolting that it made one of her children vomit.

Today, the site was a mass of debris, studded with cots, mattresses and a coat rack. Copies of the Koran and other religious books, some blood-stained, had been carefully segregated in a separate area.

But what caused the explosion is so deeply contested, so ideologically colored, that it seems it will be hard to ever reach a consensus.

Every man at the mosque today, the men at the graveyard, and the relatives of one of the wounded insisted that an American plane or helicopter had fired a missile into the mosque.

Salim Ali Hamad, whose 35-year-old brother, Ahmad Ali Hamad, lay in Falluja Hospital missing a leg, his arm and head and eye bandaged, said his brother had told him that he had been standing outside talking to the imam, Sheik Laith Khalil, when there was a "great explosion." 

The wounded man had mentioned nothing about an aircraft, his brother said, yet he was convinced that the Americans were responsible.

"More than five or six eyewitnesses saw the warplane shooting a missile at the mosque," he said. "For sure this was the Americans' action."

Capt. John Ives, head of the government support team of the Second Brigade, Third Infantry Division in Falluja, vehemently denied that, saying that blast analysis conducted by American troops suggested that it had come from within the leveled rooms. He said there were no aircraft flying in the area at the time of the explosion.

Accounts from two different neighbors — one of them Ms. Gadha, the other a woman who was afraid to give her name — seemed to support that contention.

Both said that on a quiet night, there had been no sound of an aircraft before the explosion shook the block.

"All the windows were open and we heard no aircraft," the woman who did not want to be identified said. "If a missile had been shot by an aircraft, it would be obvious; everyone would know it."

Both women had heard rumors that explosives were being stored at the mosque, and both said there were rumors it had become a locus of anti-American resistance.

Mosque members and United States officials said Mr. Khalil, the imam, had been preaching jihad for the past month.

But in the end, the truth seemed almost irrelevant. Witnesses said they had seen a helicopter or an F-16 overhead. Everyone had heard of someone seeing an aircraft, and everyone was convinced that the American troops had used the pretext of an investigation to seal off the area and cart off the missile parts.

Jasim Bedauwi, 45, a lawyer who lives nearby, said he had come running after the explosion to help pull out bodies.

Soon after, he said, the Americans arrived — without a translator — and Iraqis and Americans worked side by side, and sometimes at cross purposes.

"There was great confusion between us and the Americans," he said, and he was certain they were to blame for the blast.

"Americans want to prevent the sounds of prayer in the mosque," he said, his face red with heat and agitation, his clothing drenched with sweat. "This is like stripping Islam from here."

While some local people said the imam had died in the blast, Mr. Bedauwi maintained that he had lost a leg and suffered serious eye injuries, and had been taken to Baghdad for treatment.

Tonight, it still was not entirely clear whether Mr. Khalil had survived. A man at the Falluja Hospital said he heard that the imam had died, which would be certain to further fuel anti-American rage.

Two Baghdad hospitals said Mr. Khalil had been brought in for treatment, and then taken away.

At a third hospital, Al-Jarrah, doctors said a man from Falluja clearly wounded in an explosion, with injuries fitting those described by mosque members, had died a few minutes after being brought there this afternoon.

"My suspicion is they were trying to hide him," said Dr. A. G. Majeed, expressing bafflement at why the man had been brought to the hospital near death, some 14 hours after his companions said the Falluja explosion had taken place.

"Everything was suspicious," the doctor said.