Damascus: Syrian troops were locked in fighting on Monday with armed rebels in parts of Damascus and the second city Aleppo, monitors said, as Arab nations offered President Bashar al-Assad a "safe exit" if he gave up power.

Syria's opposition said the raging battles indicated they were "at the gates of victory" while the rebel Free Syrian Army (FSA) boasted that Assad's regime was "collapsing."

The EU meanwhile beefed up sanctions against Assad's regime on Monday and agreed to tighten an arms embargo by inspecting vessels and planes suspected of carrying arms, diplomats in Brussels said.

Residents of the capital reported hearing gunfire and explosions into the early hours of the morning in the upscale Mazzeh neighbourhood of west Damascus, while activists reported overnight shelling in several other districts of the city.

Syrian state television reported an assault on Mazzeh, calling the operation "targeted and quick."

The broadcaster showed footage of troops firing as they entered part of the neighbourhood and featured an interview with one soldier.

Regime forces also "chased the remnants of the terrorists in Barzeh," in the northeast of Damascus, the report said.

The Syrian Observatory for Human Rights said the government offensive in Barzeh, spearheaded by "the feared Fourth Brigade" commanded by Assad's powerful younger brother Maher, had triggered an exodus of residents.

The Local Coordination Committees, which organizes activists on the ground in Syria, meanwhile reported that military reinforcements were sent during the night to a number of Damascus neighbourhoods rocked by clashes since the rebels announced the launch of "Operation Damascus Volcano" a week ago.

The LCC also reported fierce clashes during the night and into the morning between rebel forces and Syrian troops in the northern city of Aleppo.

Largely excluded from the violence and protests of the country's 16-month uprising until recently, Aleppo has emerged as a new front in the battle between rebel fighters and Assad's troops.

The Britain-based Observatory said on Monday that the death toll in fighting across Syria Sunday stood at 123, including 67 civilians, 22 rebels and 34 soldiers.

The watchdog group said that more than 19,000 people have been killed since the uprising against Assad's regime began in March 2011.

The spiralling violence has alarmed Syria's neighbours and prompted a meeting late on Sunday in Doha of Arab League foreign ministers, who in a statement called on Assad to "renounce power," promising that he and his family would be offered "a safe exit."

"There is agreement on the need for the rapid resignation of President Bashar al-Assad," Qatar's Prime Minister Sheikh Hamad bin Khalifa Al-Thani told journalists after the meeting wound up in the small hours on Monday.

The Arab League called on FSA rebels and the opposition to form a transitional government of national unity along with the "de facto national authority", without detailing who that authority might be.

(Agencies)

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