United Nations observers have reached the Syrian village of Al-Kubeir where dozens of residents were massacred two days ago, activists said.

The monitors were yesterday fired at by gunmen and forced to turn back as they tried to reach the village located in the central province of Hama.

"The observers first headed to the village of Maarzaf where the victims were buried and then to Al-Kubeir to survey the damage from army shelling," activist Abdel Karim al-Hamwi said.

According to the Syrian Observatory for Human Rights, at least 55 people, including women and children, were massacred in Al-Kubeir on Wednesday by pro-regime militiamen known as shabiha.

The government has denied involvement while the international community has denounced the killings with UN chief Ban Ki-Moon warning that Syria stood on the brink of full-blown civil war.

Meanwhile, China has called for both sides in Syria to halt the violence and implement envoy Kofi Annan's peace plan, in the face of rising calls to back tougher action against President Bashar al-Assad's government.

China "strongly condemns" the deaths of innocent civilians and calls for the perpetrators to be punished, Chinese Foreign Ministry spokesman Liu Weimin told a daily news briefing.

Developments in Syria make Mr Annan's efforts more important, Mr Liu added.

China has repeatedly said it opposes external intervention in Syria.

Mr Annan said it was time to step up the pressure on Damascus to halt the violence.

"The Syrian people are bleeding," Mr Ban said. "They are angry. They want peace and dignity. Above all, they all want action.

"The danger of a civil war is imminent and real," he said, adding that "terrorists are exploiting the chaos."

Mr Ban also condemned the latest massacre of 78 people in the village of al-Qubeir in the Hama province.

He added that President Bashar al-Assad had lost all legitimacy.

Elsewhere, US ambassador to the UN Susan Rice said the Council was told that the Syrian regime had to face the consequences of its action.

The Syrian Ambassador to the UN, Bashar al-Ja'afari, said there was no justification for what was happening in his country.

The UN is also trying to supply humanitarian relief to over 1m people affected by the conflict.

But John Ging, director of operations at the UN Office for the Co-ordination of Humanitarian Affairs, told RTÉ's Morning Ireland that only 20% were being reached, and the Syrian government was responsible for this.