Activists said pro-government militia men and security forces killed at least 78 people, including children, in Syria's central province of Hama on Wednesday.     

Some of those killed in the village of Mazraat al-Qabeer were stabbed to death, the activists said, and at least 12 bodies had been burned.      

The British-based Syrian Observatory for Human Rights said its activists on the ground documented a smaller number of victims - 24 people, four of them children.     

Syria's 15-month revolt against President Bashar al-Assad's rule has grown increasingly bloody in recent months, raising concerns the country may be slipping towards civil war.     

Events inside the country are difficult to verify as Syria has restricted access to international media.     

The killings came less than two weeks after a massacre in the Syrian town of Houla, in which security forces and pro-Assad militia men known as 'shabbiha' killed 108 people, nearly half of them children.

Both have taken place during the presence of a United Nations observation mission in the country.     

The government called the Hama province killings on Wednesday a "monstrous crime" and said its forces were uprooting militants in the area.     

"Special forces are answering the calls for help from residents of Mazraat al-Qabeer and are raiding the terrorist dens. They have killed a number of them and have seized weapons and rocket-propelled grenades," it said in a news flash on Syrian state television.     

Some activists said rebels from the Free Syrian Army had been operating in the area and accused Syrian forces of using group punishment Mazraat al-Qabeer, home to a few hundred villagers and just 20 km (12 miles) from the central city of Hama.     

Syrian forces had surrounded areas close to Mazraat al-Qabeer for days and began shelling the village on Wednesday evening, local activists said.    

"The rockets were hitting people's homes and some were set ablaze. Then the militia men came in and started shooting and killing people," said a Hama-based activist who called himself Manhal. "The first reports we got were that people were being shot dead. Then some people were found stabbed."           

Many activists demanded an international investigation by the 300-strong UN force sent into Syria to observe a ceasefire deal brokered by international envoy Kofi Annan.      

The truce was hardly observed by the government or the rebels.     

"We call on international monitors to go immediately to the area," the Observatory said in a statement.     

"They should not give the excuse that their mission is only to observe the ceasefire, because many massacres have been committed during their presence in Syria."     

Activists in Hama said Mazraat al-Qabeer's residents are Sunni Muslims, the country's majority population that has led the revolt in which the UN estimates more than 10,000 people have been killed.      

They said the village neighbours an area inhabited mostly by members of minority Alawite sect, an offshoot of Shi'ite Islam to which Assad himself belongs.     

Many Alawites, and other minorities in Syria, have treated the uprising with suspicion and fear sectarian conflict similar to bloody civil wars that wracked neighbouring Lebanon and Iraq.     

Alawites dominate Syria military and political elite and the disparity between their positions and that of the less empowered Sunni majority has stirred sectarian tensions.     

"These killings aimed to absorb Alawite anger for the fighters they are losing in this fight. They want to make them feel supported by the army," the activist Manhal said, speaking to Reuters by telephone from the city of Hama.     

A government statement on Syria TV said the killings in Mazraat al-Qabeer were a conspiracy to influence a meeting among foreign powers sympathetic to the opposition in Istanbul on Wednesday and a United Nations Security Council meeting later this week. – Reuters