BEIRUT: The United States proposed an international coalition to support Syria’s opposition Sunday after Russia and China blocked a U.N. attempt to end nearly 11 months of bloodshed, raising fears that violence will escalate. Rebel soldiers said force was now the only way to oust President Bashar Assad, while the regime vowed to press its military crackdown.The threat of both sides turning to greater force after Russia and China vetoed a U.N. Security Council resolution raises the potential for Syria’s turmoil to move into even a more dangerous new phase that could degenerate into outright civil war.

The uprising inspired by other Arab Spring revolts began in March with peaceful protests against Assad, sparking a fierce crackdown by government forces. Soldiers who defected to join the uprising later began to protect protesters from attacks. In recent months the rebel soldiers, known as the Free Syrian Army have grown bolder, attacking government troops and trying establish control in pro-opposition areas. That has brought a heavier government response.

Well over 5,400 people have been killed since March, according to the U.N., and now regime opponents fear that Assad will be emboldened by the feeling he is protected by his top ally Moscow and unleash even greater violence to crush protesters. If the opposition turns overtly to armed resistance, the result could be a dramatic increase in bloodshed.

At least 56 people were killed in violence across Syria Sunday, half of them civilians, a rights group said.

The Syrian Observatory for Human Rights said 23 civilians were killed in the flashpoint province of Homs, central Syria, two in Daraya near the capital and three in Idlib, in the northwest of the country.

The Britain-based group, in a statement received in Nicosia, reported 14 military deaths in Idlib, seven in Homs, four in the southern province of Daraa and three in Zabadani near Damascus.

The commander of the Free Syrian Army told the Associated Press that after the vetoes at the U.N., “there is no other road” except military action to topple Assad.

“We consider that Syria is occupied by a criminal gang and we must liberate it from this gang,” Col. Riad al-Asaad said, speaking by telephone from Turkey. “This regime does not understand the language of politics, it only understands the language of force.”

U.S. Secretary of State Hillary Rodham Clinton warned that chances for “a brutal civil war” would increase as Syrians under attack from their government move to defend themselves, unless international steps provide another way.

Speaking to reporters in the Bulgarian capital Sofia, she called the double veto at the U.N. Security Council Saturday “a travesty.”

“Faced with a neutered Security Council, we have to redouble our efforts outside of the United Nations,” she said, calling for “friends of democratic Syria” to unite “support the Syrian people’s right to have a better future.”

The call points to the formation of a formal group of like-minded nations to coordinate aid to the Syrian opposition, similar but not identical to the Contact Group on Libya, which oversaw international help for opponents of the late Libyan leader Moammar Gadhafi. In the case of Libya, the group also coordinated NATO military operations to protect Libyan civilians, something that is not envisioned in Syria.

U.S. officials said an alliance would work to further squeeze the Assad regime by stepping up sanctions against it, bringing disparate Syrian opposition groups inside and outside the country together, providing humanitarian relief for embattled Syrian communities and working to prevent an escalation of violence by monitoring arms sales.

French Foreign Minister Alain Juppe said Sunday Europe will strengthen sanctions against Damascus to increase pressure on Assad.

Juppe also said that France would “help the Syrian opposition to structure and organize itself” and would be working to create an international group on Syria.

President Nicolas Sarkozy has proposed the creation of a “group of friends” of the Syrian people.

Juppe said Sarkozy “will take steps in the coming days to try to bring together all those who consider the current situation [in Syria] absolutely intolerable.”

The main Syrian opposition umbrella group, the Syrian National Council, backed the idea.

Radwan Ziadeh, a prominent figure in the SNC, wrote on his Facebook page that friendly countries should form an “international coalition ... whose aim will be to lead international moves to support the revolution through political and economic aid.”

A deeply sensitive question is whether such a coalition would back the Free Syrian Army. There appears to be deep hesitation among Western countries, fearing further militarization of the conflict.

Omar Idlibi, an activist with the Syrian National Council, said action by a “friends coalition” to increase sanctions and other steps would boost peaceful opposition through protests.

But, he said, it should also include support to the FSA, which he said would prevent civilians from taking up arms, worsening the conflict.

The FSA, he said, “is a national Syrian army and as the regime has the right to get help from its Russian and Iranian allies, it is the right of the opposition to ask for help from its friends in enabling the Syrian people to achieve change.” The FSA, based out of neighboring Turkey, is believed to number several thousand soldiers and it almost daily announces claims of groups of soldiers joining its ranks that cannot be confirmed. It is heavily outgunned by the powerful regime military, which still has the power to conduct focused operations that can drive the rebels out of any areas they gain control of.

But the military cannot cover everywhere at once, and FSA troops appear to be proving effective at hit-and-run attacks and have put up staunch resistance in assaults on opposition-dominated urban areas.

Early Saturday, government forces bombarded the restive central city of Homs, apparently in response to FSA attacks. Activists said the bombardment was the deadliest incident of the uprising, killing more than 200 people in a single day.

Idlibi told The Daily Star Sunday that the opposition Local Coordination Committees has so far identified 181 bodies as victims of the Homs shelling, adding that efforts are ongoing to identify more bodies.

“In the very beginning, we were only able to identify 39 bodies. The security forces have managed to take away many corpses from hospitals, and activists on the ground are still trying to come up with an accurate body count,” Idlibi said.

“The last figure that we circulated to the media today is 181, but we are sure there are more deaths.”

The regime denied any bombardment and there was no way to independently confirm the toll.