BEIRUT -- Russia and China Saturday vetoed a UN Security Council resolution aimed at ending Syria's bloodshed, despite international outrage over a devastating bombardment of the city of Homs by President Bashar Assad's forces that may have killed hundreds.

After the double veto, the U.S. Ambassador to the United Nations, Susan Rice, said the United States was "disgusted" by the vote.

Activists said more than 200 people were killed Saturday in the bloodiest episode of the nearly 11-month uprising.

The overnight onslaught on restive neighborhoods in Homs, Syria's third largest city, signaled a willingness by Assad's regime to bring a new level of violence to stamp out its opponents.

Its timing, hours before a planned vote on the UN resolution, suggested Assad was confident of his ally Russia's protection on the world stage.

Activists' reports of the death toll from the assault could not be independently confirmed.

The Syrian government denied any bombardment took place, saying the reports were opposition propaganda aimed at pressuring the United Nations. It said bodies of the dead that appeared in activists' online videos were those of people who had been kidnapped previously by "terrorists."

Residents of Homs Saturday described a night of relentless bombardment by mortars and rockets that lasted until dawn, sending them fleeing to lower floors and basements. When daylight came, dozens of buildings were left punctured by shells, facades collapsed, and some streets were stained with blood.

Tunisia decided to expel Syria's ambassador and end its recognition of Assad's regime in response to what it called a "bloody massacre" in Homs.

Angry Syrians stormed their embassies in Berlin, London, Athens, Cairo and Kuwait, clashing with guards and police and -- in Cairo -- setting fire to part of the embassy.

The bloodshed added new urgency to negotiations over the resolution, as Western and Arab nations amended drafts to overcome Russia's opposition.

"The Assad regime must come to an end," President Barack Obama said in a statement before the vote, calling on the Security Council to "stand against the Assad regime's relentless brutality."

Early drafts demanded Assad carry out an Arab League peace plan by which he would hand over his powers to his vice president and allow formation of a unity government. That was amended to an expression of support of the plan without detailing its provisions.

But Russia demanded further changes, saying the draft did not make enough demands on the armed opposition in Syria and that calls for Assad to step aside could wreck chances for a negotiated solution to the country's upheaval.

In the end, the resolution's proponents pushed ahead with a vote, challenging Moscow to veto or back down.

French Ambassador Gerard Araud said Russia and China had "made themselves complicit in a policy of repression carried out by the Assad regime."

Russian Ambassador Vitaly Churkin accused fellow council members of being inflexible, saying proposed Russian amendments had been ignored. Chinese Ambassador Li Baodong said his country joined Russia in voting against the resolution for the same reason.

Syria has been a key Russian ally since Soviet times, and Moscow remains a major arms supplier to Damascus. Russia has opposed any UN call that could be interpreted as advocating military intervention or regime change.

NewsdayTV's Doug Geed visits two wineries and a fish market, and then it's time for holiday cheer, with a visit to a bakery and poinsettia greenhouses. Credit: Randee Dadonna

Out East with Doug Geed: Wine harvests, a fish market, baked treats and poinsettias NewsdayTV's Doug Geed visits two wineries and a fish market, and then it's time for holiday cheer, with a visit to a bakery and poinsettia greenhouses.

NewsdayTV's Doug Geed visits two wineries and a fish market, and then it's time for holiday cheer, with a visit to a bakery and poinsettia greenhouses. Credit: Randee Dadonna

Out East with Doug Geed: Wine harvests, a fish market, baked treats and poinsettias NewsdayTV's Doug Geed visits two wineries and a fish market, and then it's time for holiday cheer, with a visit to a bakery and poinsettia greenhouses.

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