It was midday on a Friday, and all across Syria ­protesters were gathering for the anti-government demonstrations that have become a weekly routine since the uprising against President Bashar al-Assad’s rule began 14 months ago.

In Houla, in central Syria, this was to be a Friday like no other. By the end of the day, at least 108 people were dead, some of them killed by shelling, but most of them slaughtered in their homes. Women and children were shot at close range. Some had their throats slit, others had their eyes gouged out.

Piecing together exactly what happened in the sprawling rural area, which is more a collection of Sunni settlements than a distinct village, is difficult given the Syrian government’s restrictions on journalists and the inevitable fog that has shrouded a day of intense and multifaceted violence.

But interviews conducted by telephone and on Skype make it clear that, even by the standards of the brutal Syrian revolt, what happened in Houla on May 25 was extraordinary, an act of hatred and perhaps revenge that exposed the depth of the animosities tearing the country apart.

The events in Houla, an area northwest of the city of Homs, also exposed the powerlessness of the international community to stop what many fear is becoming the inevitable disintegration of Syria into a vicious civil war in which neighbors kill neighbors and the world looks on — as Bosnia and Rwanda experienced in an earlier era.

In a speech Sunday, Assad denied that his government was responsible and blamed the massacre on his opponents, saying it was unimaginable that security forces could do such a thing.

“Whoever did this in Houla could not be a human being but a monster. And even a monster could not carry out such an act,” he told a session of the nation’s newly chosen parliament.

Houla residents give a very different account. They blame the Syrian army and the loyalist militias known as the shabiha, which they say came from surrounding villages inhabited by members of Assad’s Shiite-affiliated Alawite sect. It is also clear that many questions remain unanswered.

The day began, as is typical on a Friday, with the men of the town gathering after prayers in at least two locations to hold demonstrations against the government. They left their wives, mothers, sisters and children at home, which is why so many of them would be among the dead.

“The people want to execute Bashar,” they chanted, according to a video of one demonstration. Held above the crowd was a big black banner, emblazoned in white with words that are chilling in light of what unfolded later in the day. “Let the world know we die with a smile on our faces,” it said.

And, as was typical on a Friday here and in many other parts of the country, shortly before 1 o’clock in the afternoon, as the protests began, Syrian troops positioned around the area began firing artillery and heavy machine guns to break up the demonstrations.

What happened next is murky, but according to at least two activists in Houla, rebel fighters attacked a Syrian army position overlooking the area. Nine soldiers were killed, including three officers, according to Ahmad Qassem, one of the activists, who said he was given the number by the local hospital. The government, in its account of the killings that day, has said that “several” of its troops were killed in an attack on a checkpoint. The rebel force also suffered casualties, Qassem said.

Whether the rebel attack was in response to the intensity of the shelling or whether the shelling intensified in response to the attack is unclear. But Houla residents described scenes of chaos as people sought shelter from the unusually heavy bombardments, attempted to rescue the wounded or tried to flee to calmer areas.

‘All were dead’

Away from the shelling, on the southwestern edge of Houla, a more sinister development began to unfold. A 25-year-old woman who gave her name as Fatima said she saw men in uniforms arriving in the late afternoon in a nearby street where members of the extended Abdel-Razzaq family lived.

Fatima said she assumed that the soldiers were conducting a routine raid, but then she began to hear shooting, which continued for at least an hour.

According to the videotaped testimony of the few survivors, the soldiers were accompanied by irregular shabiha militiamen from surrounding villages and moved through the homes shooting everyone they found.

“First they shot the other family, then they shot our family,” a teenage girl named Noura, shot in the abdomen, said on camera from a makeshift hospital bed last week. “I pretended I was dead so they wouldn’t shoot me again.”

“They were Assad’s army soldiers. I saw them, and they were Alawites,” recounted another woman, who said she also played dead after she and her four children were shot. “One was shooting, and another was finishing those who were not dead.”

Among the first to arrive at the scene after the shooting stopped was an activist who uses the name Hamza al-Omar.

He said he walked through the open door of the first house he encountered and saw the bodies of four children, a man and a woman. In an adjoining room were four more dead children and a teenager. One had been shot at close range in the jaw. Another had had an eye ripped out. Two of the children had been handcuffed before being shot.

“I went into a panic. I started running through the streets looking for wounded people. I didn’t find any,” he recalled. “All were dead. I didn’t count the houses. The scene was the same in every one. There were women stabbed in the face. Children with their throats slit. Some of the children were shot in the ear for the bullet to come out through the other ear.”

Altogether, 73 people had been killed, most of them women and children, and 62 of them members of the Abdel-Razzaq family, according to activist Abu Osama, who took videos of the scene and helped remove the bodies. Throughout the evening, he said, residents ferried the dead in cars and trucks to a mosque in the central Taldo district, even as shelling continued.

Later that night, about 3 a.m., a second round of killings occurred, claiming 12 members of the Sayid family. That incident occurred in an area under the control of Syrian security forces. The following day, the pro-government al-Dunya television station filmed the aftermath, blaming the attack on “terrorists.”

The official Syrian Arab News Agency has reported that rebels targeted members of the Sayid family because they are related to a Syrian lawmaker and refused to join the opposition.

But Houla residents say the rebels could not have been responsible because the area is tightly controlled by the Syrian army. Ali, an 11-year old boy who survived the killings by pretending he was dead, fled under cover of darkness to join his uncle in the rebel-held part of the village, which he would not have done had the rebels killed his family, Abu Osama said. In videotaped testimony, the boy accused the shabiha of carrying out the killings. He is now with the rebels and cannot be reached, activists in the town said.

Killings shock world

What provoked the killings is unclear. Were they acts of revenge, perhaps for the attack on the army checkpoint? Or for some other grievance? Mass killings are by no means a new phenomenon in Syria, nor even in Houla. In November, 11 Sunni workers there were lined up and shot dead in retaliation for the shooting of nine Alawites who had been hauled off a bus and killed the day before.

But what set last month’s massacre apart was the number of women and children among the victims, and that, for the first time, U.N. monitors were present to observe the aftermath, under the terms of a U.N.-brokered peace plan.

Their confirmation of the 108 deaths — including 49 children and 34 women — along with gruesome videos posted on the Internet of piles of dead children sent waves of revulsion rippling around the world and stirred an immediate response.

A day after the monitors confirmed the deaths, the U.N. Security Council gathered for an emergency session, issuing a statement that directly blamed Syria’s government for the violence.

Meanwhile, a humanitarian crisis is emerging, with thousands of refugees from Houla crowding into neighboring villages. The nearby town of Burj al-Qa’i has seen its population swell from 1,000 to more than 5,000 as frightened women and children have sought shelter in relatives’ homes, schools and even partly constructed buildings.

“People left everything behind as they ran for their lives,” said Marianne Gasser, head of the International Committee of the Red Cross’s office in Damascus. “There was not enough food, water and medicine for everyone, which put a great deal of pressure on the small village.”

Growing U.S. concern

Among officials in Washington, there was a palpable sense of a line being crossed, said a State Department official who sat in on meetings at which the Houla massacre was discussed. The United States, along with a dozen Western allies, expelled Syrian diplomats in protest.

“There was something in the air after Houla — you could feel it,” said the official, who spoke on the condition of anonymity. “It’s hard to put a diplomatic veneer on something like this.”

Secretary of State Hillary Rodham Clinton’s public pronouncements on Syria took on a sharper tone as she signaled impatience with the U.N. peace plan, which has clearly failed to halt the violence, and with diplomatic efforts to push for tougher sanctions against Syria in the Security Council.

During a news conference in the Danish capital, Clinton appeared to edge closer to endorsing a military option for Syria.

“Every day that goes by makes the argument for it stronger,” she said.

Yet with Russia, a close ally of Syria, stressing that it will not countenance tougher action at the United Nations against the regime in Damascus, it remained unclear whether the killings in Houla marked a turning point in the conflict or simply a new low.

In his speech Sunday, Assad was uncompromising, blaming “terrorists” and a foreign conspiracy for the violence engulfing the country.

“Today we are defending a cause and a country,” he said. “We do not do this because we like blood. A battle has been forced on us, and the result is this bloodshed that we are seeing.”

Warrick reported from Washington. Correspondent Colum Lynch in New York contributed to this report.