Syrian forces unleashed a barrage of mortars and artillery on the battered city of Homs on Saturday, killing more than 200 people in what appears to be the bloodiest episode in the nearly 11-month-old uprising, activists said.
The government denied the assault, saying the reports are part of a "hysterical campaign" of incitement by armed groups against Syria, meant to be exploited at the Security Council as it prepares to vote on a draft resolution backing an Arab call for President Bashar Assad to give up power.
Telephone calls to Khaldiyeh, the hardest hit district in Homs, were not going through, but residents of nearby areas described a hellish night of ceaseless shelling.
"Homs is on fire," said one opposition activist in a quieter area near the city, who did not want to be identified for fear of reprisal.
"All sides are attacking each other and the number of casualties is more than anyone can count," he said.
The government denied the assault and said that corpses shown in amateur videos posted online - bodies that activists said were victims of the assault - were purportedly of people kidnapped by "terrorist armed groups" who filmed them to portray them as victims of the alleged shelling.
One video showed a chaotic scene as men, with various wounds and gashes, were being tended to or were praying in what appeared to be a makeshift clinic in Khaldiyeh. Another showed a fire ravage a house in the district, as people desperately tried to put out the blaze with water.
Two main opposition groups, the British-based Syrian Observatory for Human Rights and the Local Coordination Committees, said the death toll in Homs was more than 200 people and included women and children in mortar shelling that began late Friday. More than half of the killings - about 140 - were reported in the Khaldiyeh neighborhood, they said.
"This is the worst attack of the uprising, since the uprising began in March until now," said Rami Abdul-Rahman, the head of the Observatory, which tracks violence through contacts on the ground.
The reports could not be independently confirmed.
It was not immediately clear what precipitated the attack, but there have been reports that army defectors set up checkpoints in the area and were trying to consolidate control.
Unconfirmed reports also said gunmen, possibly army defectors, had attacked a military checkpoint in Khaldiyeh, captured 17 of its members, prompting intense clashes with the military.
Homs, Syria's third largest city, is a hotbed of dissent to Assad's regime and is known to shelter a large number of army defectors known as the Free Syrian Army. The city has seen several crackdowns by security forces but many parts of it remain outside of government control.
Ammar, a resident of the Bab Tadmur district of Homs, said the real death toll exceeded 330 people, and hundreds of others were wounded. He did not elaborate.
"A few more nights like this one and Homs will be erased from the map," said the distraught man by telephone. "We are being massacred, what is the Security Council still waiting for?" he asked.
The LCC called on residents of Homs and surrounding areas to support the people of Khaldiyeh and nearby Bayada by donating blood and housing families fleeing from the bombing.
It called for sit-ins in front of all Syrian embassies and consulates in capitals across the world.
An Egyptian security official said that at least eight people were arrested, among them Syrians, after protesters attacked the Syrian Embassy in Cairo and set part of it on fire. It was the second time in around a week that activists storm the Syrian embassy in Cairo.
Egyptian activists urged people early Saturday to march to the embassy from Tahrir Square, the focal point of Egypt's protests, where a large tent has been erected in solidarity with the Syrian uprising.
In Kuwait, demonstrators stormed into the Syrian Embassy compound on Saturday, breaking windows and hoisting the flag of the opposition, witnesses there said, speaking on condition of anonymity because they were not authorized to talk to the media.
The Kuwait Society for Human Rights said one protester was slightly injured and crowds panicked when someone fired shots into the air. It was unclear who fired the shots.
The Kuwait News Agency said "a number of security personnel" were hurt but gave no details. KUNA said the interior ministry denounced the protest as a "breach of international law and norms."
Earlier on Friday, deadly clashes erupted between government troops and rebels in suburbs of the Syrian capital and villages in the south, sparking fighting that killed at least 23 people, including nine soldiers, activists said.
Assad is trying to crush the revolt with a sweeping crackdown that has so far claimed thousands of lives, but neither the government nor the protesters are backing down and clashes between the military and an increasingly bold and armed opposition has meant many parts of the country have seen relentless violence.
The U.N. Security Council will meet Saturday morning to take up a much-negotiated resolution on Syria, said a diplomat for a Western nation that sits on the council.
The diplomat spoke Friday on condition of anonymity because he was not authorized to be quoted by the media.
The move toward a vote came after U.S. Secretary of State Hillary Rodham Clinton spoke by telephone with Russian Foreign Minister Sergey Lavrov in an effort to overcome Russian opposition to any statement that explicitly calls for regime change or a military intervention in Syria.
The U.S. and its partners have ruled out military action but want the global body to endorse an Arab League plan that calls on Assad to hand power over to Syria's vice president.
Russia's deputy foreign minister, Gennady Gatilov, said Friday that Moscow could not support the resolution in its current form. But he expressed optimism that an agreement could be reached, according to state news agency RIA Novosti.
Assad's regime has been intensifying an assault against army defectors and protesters. The U.N. said weeks ago that more than 5,400 people have been killed in violence since March. Hundreds more have been killed since that tally was announced.
This program aired on February 4, 2012. The audio for this program is not available.