BEIRUT - Western powers expelled Syria's envoys on Tuesday in outrage at a massacre of 108 people, almost half of them children, but a defiant President Bashar al-Assad, backed by Russia, showed no sign of yielding to their pressure.
The killings in the town of Houla drew a chorus of condemnation from around the world, with the United Nations saying entire families were shot dead in their homes on Friday.
"Bashar al-Assad is the murderer of his people," French Foreign Minister Laurent Fabius told Le Monde. "He must relinquish power. The sooner the better." His Australian counterpart Bob Carr said: "This massacre of more than 100 men, women and children in Houla was a hideous and brutal crime."
The United States, France, Britain, Canada, Germany, Italy, Spain, Australia, the Netherlands and Bulgaria gave Syria's envoys hours or days to leave their capitals in a coordinated move that underlined Assad's diplomatic isolation.
Some had already expelled ambassadors or downgraded ties and so, like Washington, ordered out less senior charges d'affaires.
U.S. State Department spokeswoman Victoria Nuland called the Houla attack "the most unambiguous indictment to date" of Damascus's refusal to implement U.N. resolutions.
"We hold the Syrian government responsible for this slaughter of innocent lives," she said.
International peace envoy Kofi Annan, in Damascus to try to save a six-week-old peace plan that has failed to stem Syria's bloodshed, told Assad of the "grave concern of the international community about the violence in Syria", especially in Houla, his spokesman Ahmad Fawzi said after two hours of talks in Damascus.
But Assad's government denied having anything to do with the deaths, or even having heavy weapons in the area, despite the contrary evidence found by United Nations monitors.
Assad himself repeated to Annan Syria's line that "terrorist groups" - Syria's term for the rebels - were stepping up killings and kidnappings across the country.
Western countries that have called for Assad to step down are hoping that the Houla killings will tip global opinion, notably that of Syria's main protector Russia, towards more effective action against Damascus.
Carr said Syria's expelled charge d'affaires in Canberra was told to "convey a clear message to Damascus that Australians are appalled by this massacre and we will pursue a unified international response to hold those responsible to account".
SHELLS AND TANK TRACKS
U.N. monitors found spent shells and fresh tank tracks in Houla, evidence of weaponry that Syria's lightly-armed rebels do not have in their arsenal.
But the U.N. human rights office in Geneva said the bulk of the 108 mostly civilian dead in Houla had been executed at close range. Most had been shot.
Survivors told U.N. investigators that the killers were pro-Assad "shabbiha" militiamen, who in the past have assaulted and intimidated hotbeds of opposition to Assad.
"What is very clear is that this was an absolutely abominable event that took place in Houla, and at least a substantial part of it were summary executions of civilians - women and children," said Rupert Colville, spokesman for the U.N. human rights office in Geneva.
He said there were 49 children and 32 women among the victims. "At this point, it looks like entire families were shot in their houses."