Activists say multiple rocket-launchers are being used by Assad forces
Syrian forces have maintained their barrage of Homs, killing at least 50 people on Monday morning, according to a senior member of the main opposition group, the Syrian National Council.
"The tally that we have received from various activists in Homs since the shelling started this morning is 50, mostly civilians. The regime is acting as if it were immune to international intervention and has a free hand to use violence against the people," Catherine al-Talli told Reuters.
The bombardment of the city where scores of people died over the weekend continued as the US sought to build an international coalition outside the auspices of the UN which could impose further sanctions against the regime of Bashar al-Assad, and China defended its decision to join Russia in vetoing a UN resolution calling on the Syrian president to resign.
The latest attacks on several districts of Homs formed the most violent bombardment in recent days, according to one Syria-based activist who had spoken to people in the city. Homs has been a centre of resistance during the 11-month uprising, in which more than 6,000 people have died.
A makeshift hospital in the neighbourhood of Baba Amr was among the targets hit by Monday's bombardment, according to the Local Co-ordinating Committees activist group.
One resident told Reuters that around 150 people had been wounded. "They want to drive the Free Syrian Army out," said Hussein Nader, referring to the rebel force of army deserters and gunmen. "Rockets are falling seconds apart on the same target."
Another local activist said multiple rocket-launchers were being used by Assad forces. Such claims have not been independently verified. Explosions could be heard and smoke could be seen rising from some buildings in live footage being broadcast by Arab satellite television stations.
In the Khalidiyeh district of the city, "we did not sleep all night", activist Majd Amer told Associated Press. "The regime is committing organised crimes." Amer said shelling had started at 3am local time, and most residents living on high floors either fled to shelters or to lower floors. Electricity was also cut.
There were also claims that a military post in the north-east of the country had destroyed over by Syrian army deserters overnight.
Three officers were killed and 19 soldiers captured in the attack, according to the London-based Syrian Observatory for Human Rights. No deserters were killed in the attack on the village of al-Bara in the Edleb region, said the group.
Activists also said Zabadani, a town north-west of Damascus near the Lebanese border that has been largely under the control of Assad's opponents for weeks, had come under fire on Monday.
Anti-government activists say they fear that the veto will embolden Assad's regime, pushing the country into outright civil war.
Hillary Clinton said the US would work with other nations to try to tighten "regional and national" sanctions against Assad's government "to dry up the sources of funding and the arms shipments that are keeping the regime's war machine going".
"We will work to expose those who are still funding the regime and sending it weapons that are used against defenceless Syrians, including women and children," she said. "We will work with the friends of a democratic Syria around the world to support the opposition's peaceful political plans for change."
Clinton did not say what the new group would set out to achieve. But it appeared that the US might seek to help organise a "Friends of Syria" group – proposed by French President Nicolas Sarkozy after the veto – to advance the Arab League initiative given the inability to make headway at the UN because of Russian and Chinese opposition.
All 13 other members of the security council voted to back the resolution, which would have "fully supported" the Arab League plan for Assad to cede powers to a deputy, a withdrawal of troops from towns and a start to a transition to democracy.
Russia said the resolution was biased and would have meant taking sides in a civil war. Syria is Moscow's only big ally in the Middle East, home to a Russian naval base and client for its arms. China's veto appeared to follow Russia's lead.
China's state-run media said western intervention in Libya, Afghanistan and Iraq showed the error of forced regime change. "Currently, the situation in Syria is extremely complex. Simplistically supporting one side and suppressing the other might seem a helpful way of turning things around, but in fact it would be sowing fresh seeds of disaster," the People's Daily said.