Syria's regime and opposition on Friday accused each other of killing more than 150 people in Treimsa village, with the latest carnage in the 16-month uprising triggering calls for tougher UN action.
Britain and France joined Syria's opposition in urging the UN Security Council to pass a binding resolution against Damascus, which pointed the finger at the "bloodthirsty media" and "terrorists" seeking intervention.
Security Council envoys failed on Thursday to make any headway in talks on rival Russian and Western draft resolutions on Syria, as Moscow spurned calls for sanctions against President Bashar al-Assad's regime.
The Syrian Observatory for Human Rights said regime troops with tanks and helicopter gunships were backed by militias armed with guns and knives as more than 150 people were slain in Treimsa on Thursday.
Rebel leader Abu Mohamad, whose fighters are based near the Hama province village in central Syria, said more than 200 people were slaughtered.
"Several dozen rebel fighters were among those killed," said the Observatory, adding only around 40 of the dead had been identified, while 30 were burned and 18 were "summarily executed."
"Some are estimating higher numbers, but even at around 150, especially considering how small the town is, this might be the biggest massacre committed in Syria since the start of the revolution," the Observatory's head Rami Abdel Rahman told AFP.
"The army must have got the green light to commit a massacre of this scale, and I bear President Bashar al-Assad responsible for the killing."
An activist at the anti-regime Sham News Network said most of the dead were rebels and that the bloodbath took place when pro-regime forces retaliated following a rebel Free Syrian Army (FSA) attack on an army convoy.
"At this stage, though we do not yet have the final count, the number of civilians killed by shelling is not more than seven," the activist who identified himself as Jaafar told AFP. "The rest were members of the Free Syrian Army."
"An army convoy was on its way to the region of Hama when it was attacked by the FSA," he said.
"The army staged a counter-attack with the support of (pro-regime) reinforcements from (nearby) Alawite villages. The FSA resisted for an hour before it was defeated."
If confirmed, the killing at Treimsa in the central province of Hama would rival the massacre at Houla on May 25, when a pro-Assad militia and government forces were accused of killing at least 108 people.
The opposition Syrian National Council urged the Security Council to pass a binding resolution against Assad's regime.
"To stop this bloody madness which threatens the entity of Syria, as well as peace and the security in the region and in the world, requires an urgent and sharp resolution of the Security Council under Chapter VII (of the UN Charter) which protects the Syrian people," it said.
Chapter VII allows for punitive measures against regimes considered a threat to the peace, including economic sanctions and military intervention.
France called for "stiffened resolve... with the threat of sanctions from the Security Council."
British Foreign Secretary William Hague called for an investigation to establish what occurred in Treimsa and for "urgent action" at the Security Council.
Damascus said the massacre was staged in a bid to provoke UN-backed intervention.
"The bloodthirsty media in collaboration with gangs of armed terrorists massacred residents of Treimsa village ... to sway public opinion against Syria and its people and provoke international intervention on the eve of a UN Security Council meeting," SANA state news agency said.
Rebel leader Abu Mohamad said regime forces pounded Treimsa for 10 hours from 11:00 am on Thursday, but an activist who identified himself as Abu Ghazi said it began at daybreak and lasted five hours longer.
"That was followed by clashes with the Free Syrian Army," said Abu Ghazi.
"The number of martyrs is very high partly because the army shelled a mosque where scores of people had taken shelter, to treat the wounded and hide from the bombs."
The village, which had a population of 7,000, he said, "is empty now. Everyone is dead or has run away."
Treimsa is near Al-Kubeir, where at least 55 people were killed on July 6, according to the Observatory. Like Al-Kubeir, Treimsa is a majority Sunni village situated near Alawite hamlets.
Assad belongs to the Alawite community -- an offshoot of Shiite Islam -- although the vast majority of Syrians are Sunni.
Spontaneous protests had begun at night to denounce the Treimsa killings, and they continued on Friday under the rallying cry: "Remove Kofi Annan, the servant of Assad and Iran."
In Hama city, scores of people emerged from mosques after weekly Muslim prayers, chanting and carrying banners in honour of those killed in Treimsa, according to YouTube videos.
"Whoever kills his people is a traitor," they chanted in Douma, a rebel stronghold near Damascus.
At least another 29 people were killed on Friday across Syria, among them 18 soldiers, seven rebels and four civilians, said the Observatory.
In New York, the Security Council wrangled over the future of the troubled UN observer mission to Syria after Russia and the West proposed rival resolutions on renewing its mandate, which expires on July 20.
Mission chief Major General Robert Mood said his team was ready to go to Treisma if a ceasefire is in place.
Annan is on Monday to meet Russian Foreign Minister Sergei Lavrov about the crisis and "the chances of an internal Syrian solution," Russia's ITAR-TASS news agency said in a report confirmed by the envoy's office.
Source: AFP Global Edition