Activists say Syrian troops are heavily 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 hit four neighborhoods in the central protest city Friday 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.” It also endorsed an Arab League plan for a democratic transition in Syria, requiring Mr. Assad to hand power to a deputy and form a unity government to prepare for internationally-supervised elections.

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.

Russian Deputy Foreign Minister Gennady Gatilov called the resolution “unbalanced,” saying it did not make any demands of Syrian opposition groups, including rebels who took up arms in response to the government crackdown on peaceful protesters. Syria is a key military ally of Russia.

The General Assembly resolution did not mention an Arab League proposal to form a joint Arab-U.N. peacekeeping force for Syria. The VOA correspondent says Egypt's U.N. ambassador, Maged Abdelaziz, told reporters that the league still plans to bring up the peacekeeping proposal at the Security Council.

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.