DAMASCUS  - The Syrian government denied on Sunday its forces were responsible for killing 92 people, a third of them children, in the central city of Houla as Arab and Western states accused it of a massacre.

The government was "not at all" responsible for the massacre in the central town of Houla that sparked an international outcry, foreign ministry spokesman Jihad al-Makdissi said.

Blaming "terrorists" for the killings on Friday and Saturday, the spokesman said the government had opened an investigation. Makdissi added that UN-Arab envoy to Syria, Kofi Annan, was expected to arrive in Damascus on Monday, although there was no confirmation from the peace envoy's spokesman.

"We are under strict instructions not to disclose travel plans," said Ahmad Fawzi in Geneva.

Arab and Western governments have expressed outrage at the "massacre" in Houla.

The rebel Free Syrian Army warned that unless the international community took concrete action it would no longer be bound by Annan's UN-backed peace plan that was supposed to start with a ceasefire last month.

Makdissi called for a return to "dialogue and the negotiation table" after people took to the streets in dozens of towns and cities across Syria on Saturday to denounce the Houla killings and call for the fall of the regime.

The head of a UN observer mission, deployed under Annan's plan, warned on Saturday of "civil war" in Syria after his observers counted more than 92 bodies, 32 of them children, in Houla. Amid mounting calls for world action to halt the bloodshed, UN Secretary General Ban Ki-moon joined the chorus of international condemnation.

"This appalling and brutal crime, involving indiscriminate and disproportionate use of force, is a flagrant violation of international law," a UN spokesman quoted Ban and Annan as saying.

Condemnation also poured in from Britain, France and Germany, with French Foreign Minister Laurent Fabius saying he was making "immediate arrangements" for a meeting of the Friends of Syria group that backs the opposition.

Violence raged on Sunday across the country, with rebel bastion Rastan, in central Homs, coming under a 14th consecutive day of artillery fire, a human rights watchdog said. "The town is being hit at a rate of two shells a minute," the Britain-based Syrian Observatory said.

According to the Observatory, at least eight people were killed in violence across Syria on Sunday. In northwest Idlib's Khan Sheikhun, a 16-year-old girl and an 11-year-old boy were killed when their town was shelled, the Britain-based monitoring group said. Mood confirmed that artillery and tanks had pounded Houla and called "on the Syrian government to cease the use of heavy weapons and to all parties to cease violence in all its forms."

Meanwhile, Arab League foreign ministers are to hold an emergency meeting on a massacre in Syria in which UN observers say government forces killed 92 people, the bloc's current president Kuwait said on Sunday.

"Kuwait will contact members of the Arab League to hold an emergency ministerial meeting to study the situation and take measures to put an end to the oppressive practices against the Syrian people," said a foreign ministry statement cited by the official KUNA news agency.

Meanwhile, Britain is to haul in Syria's top diplomat in London following the killing of 92 people, the Foreign Office said Sunday.

Syria's charge d'affaires - their ambassador has been withdrawn - will be given a diplomatic dressing-down by one of the top Foreign Office civil servants on Monday so Britain can stress its "condemnation" over the incident.

"Following the horrifying massacre of innocent civilians in Houla, the Foreign Secretary, William Hague, has instructed that the Syrian charge d'affaires be summoned to the Foreign and Commonwealth Office," a statement said.

"On Monday, May 28 he will meet political director Sir Geoffrey Adams who will make clear our condemnation of the Syrian regime's actions."