BEIRUT, May 26: Government troops shelled a string of villages in central Syria before pro-regime thugs swept through the area, shooting people in the streets and in their homes in attacks that killed more than 90 people, activists said on Saturday.

The assault on Houla, an area northwest of the central city of Homs, is one of the bloodiest single events in Syria's 15-month-old uprising.

Activists from the region said regime forces peppered Houla with mortars following a large anti-regime protest on Friday. After the bombardment, pro-government thugs known as shabiha raided the villages, killing men on the streets and stabbing women and children in their houses.

Amateur videos posted online showed scores of dead covered in sheets and blankets, some covered with chunks of ice to preserve then until burial. One video showed 14 dead children lined up on the ground, shoulder to shoulder. Another had at least a dozen more, some with holes in their heads and faces, lying on what appears to be the floor of a mosque.

The Syrian government blamed the massacre on “armed terrorist groups” but provided no details or death toll.

The killings strike a stiff blow to an international peace plan brokered by envoy Kofi Annan meant to end the violence in Syria. The basis of the plan is a cease-fire between President Bashar Assad's forces and rebels seeking to topple the Syrian regime. It was supposed to start on April 12 but has never really taken hold, with pockets of daily violence.

The UN put the death toll weeks ago at more than 9,000. Hundreds have been killed since.

UN. Secretary-General Ban Ki-moon said on Friday that there had only been “small progress” on implementing the plan and blamed the Syrian government for much of the “unacceptable levels of violence and abuses”. Annan is supposed to visit Syria soon to check on the plan’s progress, though no date has been announced.

On Saturday, French Foreign Minister Laurent Fabius condemned the attack on Houla, saying that “with these new crimes, this murderous regime pushes Syria further into horror and threatens regional stability.”

Abu Yazan, a local activist reached via Skype, said regime forces fired shells at the villages that make up Houla, an area about 40 kilometres northwest of the city of Homs after an anti-regime demonstration on Friday.

He said local rebels fighting under the banner of the Free Syrian Army tried to fight the army off in clashes around the area before pro-regime thugs known as shabiha stormed the villages, raiding homes and shooting at civilians.

The Britain-based Syrian Observatory for Human Rights said more than 90 people were killed in the Houla area. Abu Yazan said 106 people were killed, most of them in the village of Taldaw. More than 40 were children, he said.

“They killed entire families, from parents on down to children, but they focused on the children,” he said.

Another activist, Abu Walid, said that many of the women and children had stab wounds.

The activists said the Houla killings appeared to be sectarian, raising fears that Syria’s uprising, which started in March 2011 with protests calling for political reform, is edging closer to the type of sectarian war that tore apart its eastern neighbour, Iraq.

The UN has sent more then 250 military observers to Syria to try to salvage the cease-fire, and a spokesman for the team said they visited Houla on Saturday.

One Houla activist said the observers' visit would not help and could cause the government to attack again.

“As soon as they came we asked them to leave because many areas they go to get attacked,” Abu Suleiman said via Skype. “We don't want them to get near us.”

Also Saturday, the expected release of a group of Lebanese Shias who were kidnapped in Syria this week appeared to hit a snag, a day after the Lebanese government confirmed the men had been freed and were on their way to Beirut.—AP