Damascus:
UN-Arab envoy Kofi Annan headed to Damascus on Monday in a bid to salvage his battered peace plan a day after the UN condemned the Syrian regime's use of artillery in a massacre that killed more than 100 people.
The former UN chief was to meet Foreign Minister Walid Muallem later on Monday ahead of talks with President Bashar al-Assad on Tuesday, a Syrian official said on condition of anonymity.
Mr Annan's six-point blueprint was supposed to begin with a ceasefire from April 12 but it has been broken daily and 87 people were killed on Sunday in one of the deadliest days since its nominal start, a watchdog said.
Thirty-four of the dead were killed in the flashpoint central city of Hama when government forces bombarded residential area following clashes with rebel fighters, the Syrian Observatory for Human Rights said.
"Hama is like a ghost city," an activist told AFP by telephone from the city on Monday.
"We are very afraid now, because the regime troops are surrounding the areas where there was fighting, and we fear there might be a new attack," the activist said.
Rami Abdel Rahman of the Syrian Observatory said there was no excuse for the shelling of civilian neighbourhoods. "Even if there were clashes between regime and rebel forces, the army should never arbitrarily bomb residential areas, which is what they did," he told AFP.
The shelling came despite an international outcry over the deaths of 108 people in an assault on the central town of Houla on Friday and Saturday.
The United Nations says that among them were 49 children and 34 women, many gruesomely blown to bits or shot dead at point blank range.
The UN Security Council on Sunday strongly condemned the government's role through its heavy artillery assault. Its statement however did little to bring the international powers together to end the crisis.
Britain and France had proposed a text making an even stronger condemnation of the Assad government. But Russia would not agree on the wording and demanded a special meeting before approving the eventual statement.
The United States and European nations say the killings are a new sign of the ruthlessness of the Assad government.
"The evidence is not murky and there is a clear footprint of the government in this massacre," said Peter Wittig, Germany's UN ambassador.
Russia disputes the evidence and continues to defend its key Middle East ally.
"We don't believe that the Syrian government would be interested in spoiling the visit of special envoy (Annan), a very important visit during which we expect a lot of progress," said Igor Pankin, Russia's deputy UN ambassador.
"It is difficult to imagine that the Syrian government would not only shell... but also use point-black execution" against dozens of women and children, he said.
Syria's UN envoy Bashar Jaafari said accusations of government responsibility were part of a "tsunami of lies" against Damascus.
Russia and the Syrian government continue to blame opposition groups and foreign extremists for much of the trouble.
The Free Syrian Army and other rebels meanwhile say that the Houla massacre is another reason why they should not respect the ceasefire that Mr Annan brokered but which has never taken hold.
In Istanbul, exiled opposition head Burhan Ghalioun on Sunday called for a "battle of liberation and dignity" against the regime until the United Nations allows an international military intervention.
The Free Syrian Army warned that unless the international community took concrete action it would no longer be bound by Mr Annan's peace plan.
"The Annan plan is not dead," Britain's UN ambassador Mark Lyall Grant said on Sunday. But in talks on Syria on Wednesday, the council needs "to have a serious strategic discussion" about the Annan plan and what the Security Council can do to help the special envoy make it work.
"With this new crime, the assassin regime of Bashar al-Assad is taking Syria deeper into horror," said France's deputy UN ambassador Martin Briens. "The Syrian regime cannot carry on forever violating its obligations -- without risking the end of the Annan plan."
UN leader Ban Ki-moon says there is no "Plan B" if the Annan plan crashes however. Russian and Chinese opposition -- as veto-wielding permanent members -- means the UN Security Council would never approve international military action as it did in Libya last year.
A growing concern for the international community is the more than 280 UN observers now deployed in Syria as part of the Annan plan.
Ban said Sunday that the Houla massacre had added to pressure on the monitors -- the first UN force to be thrown unarmed into a conflict with a non-existent ceasefire.
"United Nations observers are facing increasing criticism for not stopping the violence and, in some quarters, even being blamed for an increase," Ban told the Security Council.
The UN force is "in a perilous position," he added.