Activists say Syrian troops are shelling rebel-held areas in the central city of Homs, just one day after the U.N. General Assembly condemned the regime for violating human rights in its crackdown.

The activists said tank fire and artillery shelling Friday hit four neighborhoods in the central city which has spearheaded the 11-month uprising against President Bashar al-Assad.

On Thursday, U.N. Secretary-General Ban Ki-moon accused the Assad government of “almost certain” crimes against humanity.

The U.N. General Assembly also passed a resolution, approved by 137 of the assembly's 193 member states, calling on Mr. Assad's autocratic government to “immediately put an end to attacks against civilians.”

Frustrated by the lack of a U.N. Security Council action, British Prime Minister David Cameron, who met his French counterpart in Paris for talks on Friday, said Britain and France both support the creation of the “Friends of Syria”, an international coalition that world leaders are expected to discuss next week at a conference in Tunisia.

The British prime minister said, “What is happening in Syria is appalling, you have a government that is butchering and murdering its own people, and it is horrific what is taking place and that's why it's so important that the world comes together and the world acts as decisively as it can.”

French President Nicholas Sarkozy, meanwhile, sent a strong message to Syrian opposition groups to unite so that the outside world can better support them in overthrowing the Syrian government.

He said, “We cannot bring about a Syrian revolution without the Syrian people and I am sure you understand what I mean by this. We cannot bring this about if the Syrian opposition doesn't unite and organize to help us to help them. We will not accept that a dictator is allowed to massacre its own people, but the revolution cannot come from the outside, it must be born from within.”

General Assembly resolutions are non-binding, but reflect world opinion on major issues. Eleven nations joined Syria in voting against the resolution, most notably Russia and China, which vetoed a similar measure in the U.N. Security Council earlier this month.

The VOA correspondent in New York says other nations whose ambassadors spoke against the General Assembly resolution included Iran, North Korea, Bolivia and Venezuela.

The U.S. ambassador to the U.N., Susan Rice, said the assembly sent a clear message to the Syrian people that “the world is with you” and President Assad “has never been more isolated.”

Syria's ambassador to the U.N., Bashar Jaafari, accused the resolution's Arab co-sponsors of colluding with “terrorists” to undermine the Syrian government.

Chinese Vice Foreign Minister Zhai Jun is due in Syria Friday for talks with Syrian officials on resolving the conflict. The vice foreign minister met with a Syrian opposition delegation in the Chinese capital last week.

Rights groups say Mr. Assad's crackdown on dissent has killed more than 6,000 people since last March. There was no way to verify the latest casualty figures independently because Syria tightly restricts foreign media.