BEIRUT -- Row upon row of bloodied bodies wrapped in colorful blankets laid out on a mosque floor in a Damascus suburb. Long narrow graves tightly packed with dozens of victims. Nestled among them, two babies were wrapped in a single blood-soaked blanket, a yellow pacifier dangling beside them from a palm frond.

Evidence mounted on Sunday of a new massacre in Syria's deepening civil war, with activists reporting a killing spree by government forces after they seized the suburb of Daraya from rebel control three days ago. Reports of the death toll ranged from more than 300 to as many as 600.

Video footage posted by activists showed lineups of corpses, many of them men with gunshot wounds to their heads. During mass burials on Sunday, bodies were sprayed with water from hoses -- a substitute for the ritual washing prescribed by Islam in the face of so many dead.

The gruesome images appeared to expose the lengths to which the regime of authoritarian President Bashar Assad was willing to go to put down the rebellion that first broke out in March last year.

In an ominous commentary, Assad was quoted by his official media as saying his regime would carry on fighting "whatever the price."

"It is clear that was collective punishment," Khaled Al-Shami, an activist from Damascus, said of the killings in Daraya. "I am certain that the coming days will reveal more massacres, but by then others will have taken place and people will forget about Daraya."

The video footage and death toll were impossible to independently verify because of severe restrictions on media coverage of the conflict. However activists and residents have reported excessive use of force by the regime, with indiscriminate bombing from the air and ground.

"Daraya, a city of dignity, has paid a heavy price for demanding freedom," the Local Coordination Committees activist group said in a statement, adding that the Assad regime targeted residents with executions and revenge killings "regardless of whether they were men, women or children."

With a population of about 200,000, Daraya is part of "Rural Damascus," or Reef Damascus, a province that includes the capital's suburbs and farmland. It has been a stronghold of support for the rebels fighting the government since the start of the uprising, posing a particularly grave threat to Assad's seat of power.

Troops backed by tanks stormed the town on Thursday after a siege that lasted several days during which no one was allowed to enter or leave, activists and residents said. The rebels were no match for Assad's tanks and helicopter gunships.

Most of the killings, according to activists, took place Friday and Saturday. But the extent of the carnage only began to be revealed Sunday.

The British-based activist group Syrian Observatory for Human Rights said 45 more dead bodies were found in the streets of Daraya on Sunday and that they had been killed by "gunfire and summary executions." Among them, it said, were three women and two children. It said the toll for the past week was at least 320.

Rami Abdul-Rahman, the observatory's director, said activists on the ground identified 207 of the 320.

The Local Coordination Committees also reported 45 deaths Sunday and said 300 bodies were discovered a day earlier in Daraya, with a total of 633 people killed there since the government launched its assault. It said 1,755 people had been detained in Daraya, suggesting that hundreds more might turn up dead.

Video footage posted by the group showed rows of bodies wrapped in blood-soaked blankets, with date palms and tree branches strewn over them. Someone was shown spraying the bodies with a hose, a substitute for the ritual washing of the dead prescribed by Islam's teachings.

Another video posted on the Internet and dated Saturday showed dozens of bodies on the blood-splattered floor of a mosque. Pieces of paper were placed on some of them, presumably identifying them. The anonymous commentator, his voice choking, said there were at least 150 bodies there and blamed a pro-government militia known as shabiha for the killings.

A third video showed several dozen bodies, some in white shrouds, stacked next to each other in what appeared to be a courtyard of a mosque or a large home.

A photograph circulated by the Shaam News Network showed two babies, their pajama tops soaked in blood, wrapped in a blanket decorated with blue and white flowers. It said they were among dozens of victims buried Sunday in a mass grave.

Al-Shami, the Damascus activist, and Abdul-Rahman said Daraya was under a de facto curfew Sunday, as Assad's forces carried out house-to-house searches as well as execution-style killings. The Internet had been disconnected by authorities, said Al-Shami, who did not use his real name for fear of reprisals.

The fighting in Dayara, according to activists, is being carried out by the Syrian army's elite 4th Division, which is led by Assad's brother, Maher. The division is by far the best trained and armed outfit and is primarily tasked with securing the capital.

One theory as to what triggered such a large-scale military operation was that rebel mortar teams have targeted the capital's military Mazzeh airport, which abuts Daraya. Activists said the regime was intent on protecting the facility as a potential gateway out of the capital for Assad and pillars of his regime if the situation dramatically worsens.

Britain's Middle East minister, Alistair Burt, said on Sunday that if confirmed, the Daraya killings "would be an atrocity on a new scale requiring unequivocal condemnation from the entire international community."

Still, the battle for Daraya showed the regime to be struggling to control Damascus and its suburbs, though the firepower available to it is far superior to anything the rebels might have. Government forces are stretched thin, with a major ongoing battle for control of the nation's largest city, Aleppo in the north, as well as smaller-scale operations in the east and south.

A total of 213 people were killed in fighting Sunday, according to the Observatory.

Activists say more than 20,000 people have died in 17 months of fighting in Syria, as an uprising that started with peaceful protests against Assad's rule has morphed into a civil war.

In Damascus, meanwhile, Syrian Vice-President Farouk al-Sharaa appeared in public on Sunday for the first time in weeks, ending rumours that he had defected. Reporters saw him get out of his car and walk to his office for a meeting with Alaeddin Boroujerdi, head of Iran's powerful parliamentary committee on national security and foreign policy.

There have been a series of high-level defections from the Assad regime in the past few months.

Al-Sharaa was last seen at the funeral of four top security officials killed in a blast in Damascus on July 18. Since then, there had been rumours that he defected to Jordan, though al-Sharaa's office and Jordan repeatedly denied that.

On the Turkish-Syrian border, meanwhile, several thousand Syrians gathered at the Bab al-Salameh border crossing, having fled airstrikes in their northern towns and villages. They squatted on the sidewalks of three large hangars once used for cargo inspections of trucks. Some said they had been there a week or more.

Mohammed Abdel-Hay, 41, said his family of seven fled the village of Marea after a regime warplane bombed it last week, destroying a house and killing two people.

"They shelled us and we didn't leave. They hit us with helicopters and we didn't leave. Then they brought warplanes that dropped huge bombs that destroyed entire houses and we left," he said.

Since then, the family had staked out a patch of sidewalk where they sat on a plastic mat with a few grain sacks full of clothes.

Mustafa Khatib, 40, a middle school principal from the same village, was living in the hangar with his wife and their five children.

It had only one set of latrines, which the women and children used; the men used nearby fields. Water was in short supply and Khatib said he hadn't showered in a week. He said he'd eaten only a piece of bread and a hard-boiled egg all day Sunday.

Like most of the families, he hoped to get into a refugee camp in Turkey, but had been told there was no room.

"We'll stay here and wait and see," he said. "Every day, we ask and they tell us today or tomorrow, but they've been saying that for a week and we're still here."