Syrian government forces retook much of the southern Tadamun district of Damascus on Saturday after heavy fighting broke out between government forces and regime activists.

According to the Britain-based Syrian Observatory for Human Rights, army shelling of the neighborhood was "the most violent that the district has seen."

In Syria's largest city Aleppo, meanwhile, activists said Syrian government forces stepped up their onslaught on rebel-held areas. Abu Omar al-Halabi, a commander in the rebel Free Syrian Army, said rebel forces were forced to make a "tactical retreat" from the district of Izaa overnight, after the Syrian army used fighter jets to strafe the area.

Clashes reportedly erupted when rebel fighters attempted to storm the state television building, which is located in the area.

"Fierce clashes took place between our fighters and the regime troops near the Syrian television station in Aleppo," al-Halabi told German news agency dpa.

State news agency SANA confirmed the incident on Saturday, reporting that "mercenary terrorist groups attacked civilians and the state TV building while the army defended it."

The Syrian Observatory claims at least 13 people were killed in fighting across the country on Saturday, although this could not be verified independently.

Russia denounces vote

Saturday's fighting comes a day after the UN General Assembly adopted a resolution condemning the Security Council for its failure to bring an end to the 17-month conflict. Friday's vote was passed in the 193-nation assembly with an overwhelming majority of 133 votes to 12, with 31 abstentions.

The Saudi-drafted text stated that UN members deplored "the Security Council failure to agree on measures" to make the Syrian government carry out UN demands to end the crisis.

Pointing the finger at the Syrian regime, it expressed "grave concern" at the escalation of violence across the country and denounced the regime's use of "heavy weapons." It also called for "an inclusive Syrian-led political transition to a democratic, pluralistic political system."

In continued opposition to international measures on Syria, Russia and China were among the countries to vote against the non-binding resolution.

Russia's UN Ambassador Vitaly Churkin blasted the assembly on Friday for taking action which he described as "harmful" to peace efforts.

He told the assembly that the resolution was tantamount to a show of support for armed rebels who are engaged in a fight to oust President Assad.

"Behind the facade of humanitarian rhetoric, the resolution hides a blatant support for the armed opposition," Churkin said.

Russia and China have vetoed three Security Council resolutions and are widely blamed for stalling international efforts to end the violence.

Although Friday's assembly vote is not binding on veto powers within the 15-member Security Council, it can carry moral weight and has been seen as a symbolic gesture to push the UN into action.

ccp/tj (Reuters, AP, AFP, dpa)