Syrian President Bashar al-Assad's forces, disregarding U.N. condemnation of their violent suppression of a nationwide revolt, renewed a bombardment of the opposition stronghold of Homs and attacks on rebels in Deraa Friday.

Demonstrations against Assad were reported by activists in several cities across Syria, including the capital Damascus and the commercial hub Aleppo, after Friday Muslim prayers despite the threat of violence from security forces.

China's vice foreign minister, Zhai Jun, arrived in Damascus in a show of support for Assad after the U.N. General Assembly passed a resolution telling the increasingly isolated president to halt the crackdown and surrender power.

China, along with Russia, had voted against the motion and says Syria must be allowed to resolve its problems without being dictated terms by foreign powers.

Its stance on Syria will withstand the test of history, Foreign Ministry spokesman Liu Weimin said in Beijing.

Zhai said before leaving for Damascus: China does not approve of the use of force to interfere in Syria or the forceful pushing of a so-called regime change.

China's embassy in Damascus said Zhai would meet his Syrian counterpart Friday night, hold talks with Assad Saturday and also meet opposition figures in Damascus. It was not known if he had any particular message for Assad or if he would try to persuade him to call off the military operation.

Even as Zhai landed in Damascus, government forces pummelled opposition-held areas of the strategic western city of Homs, now under fire for two weeks.

An intense bombardment hit the mainly Sunni Muslim area of Baba Amro after Alawite-led troops, backed by armour, advanced from neighbouring Inshaat, opposition activists there said.

They are mostly firing rockets that directly fall onto buildings and mortar rounds now and then. Only Karama street now separates Baba Amro from the army at Inshaat, activist Aba Iyad said by satellite phone from Baba Amro.

In Idlib, capital of the rugged northwestern province on the border with Turkey, two residents told Reuters that tanks ringed the city at dawn. Residents anticipated an assault.

At every entrance of Idlib several tanks deployed along with pick-up trucks used for troop transport, said one resident, who gave his name as Fouad.

In Deraa, a city on the Jordanian border where the revolt erupted nearly a year ago, explosions and machinegun fire echoed through districts under attack by troops, residents said.

The military has also opened a new offensive in Hama, a city with a bloody history of resistance to Assad's late father. The Assad clan are Alawites, an offshoot of Shi'ite Islam, in the majority Sunni country.

DEFIANCE

People defied security forces to demonstrate in the streets of towns and cities, as they have done most Fridays since the revolt against Assad's 11-year rule broke out.

At the Zein al-Abideen mosque in central Damascus, YouTube footage provided by activists showed about 2,000 worshippers chanting and clapping Homs we are you till death...the people want the downfall of the regime.

In Aleppo and surrounding suburbs, they chanted: Please God speed up your victory. Video uploaded from Rastan, a heavily hit city in Homs province, showed hundreds crowded along a street in the rain, clapping their hands over their heads.

It was not possible to verify the video and reports and Syrian authorities tightly restrict media access to the country.

STAY OR GO?

The U.N. assembly vote in New York Thursday showed Assad had few foreign sympathisers left. The vote went 137-12 in favor with 17 abstentions on a resolution endorsing an Arab League plan that calls for him to step down.

The assembly vote, unlike Security Council resolutions, has no legal force but it reflected global revulsion at the ferocity of the crackdown in which security forces have killed several thousand civilians since last March.

Beirut-based political commentator Rami Khouri told Reuters that the vote was important. There's overwhelming global support for the opposition. It keeps the pressure on and the opposition can say they have global legitimacy. I think his days are numbered. But we still don't know how long he can hold on.

Assad, who succeeded his father Hafez in 2000 after he had ruled for 30 years, retains crucial support from Russia and China as well as backing from Iran, itself at odds with the West. Moscow has long-standing strategic interests in Syria, including a naval base, and is Syria's main arms supplier.

ABUSES

The uprising started out as civilian protests across the country last March but now includes a parallel armed struggle spearheaded by the Free Syria Army.

The rebel fighters have yet to do much more than stage hit-and-run attacks and skirmishes. But Western and Arab powers fear the crisis is sliding into a civil war which could inflame the region's patchwork of religious, ethnic and political rivalries.

Assad portrays the opposition as foreign-backed terrorists and has promised reforms while rejecting the idea of surrendering power.

Wednesday he announced a referendum on a draft constitution on February 26 followed by a multi-party parliamentary election, a move swiftly dismissed the opposition and the West.

It was not clear how a vote could be held in country with a repressed population and in a state of open revolt. But Assad told a visiting Mauritanian official Friday that political reforms have to march parallel with returning security and stability and protecting citizens, the state news agency said.

U.N. Secretary General Ban Ki-moon and other world leaders have decried the violence and are considering steps to get humanitarian aid to civilians suffering in embattled areas.

But the West has ruled out military intervention of the type that helped topple Muammar Gaddafi in Libya last year and must pin its hopes on a bringing together a fragmented opposition movement which includes activists inside Syria, armed rebels and politicians in exile.

(Additional reporting by Mariam Karouny and Dominic Evans in Beirut; Writing by Angus MacSwan in Beirut; Editing by Mark Heinrich)