Fierce fighting has erupted in Damascus, inching closer to the heart of the Syrian capital as troops backed by armoured vehicles clash with rebel fighters, ABC News reported.


Activists have claimed that the army is losing control of some areas of the city as the fighting intensifies, with protesters reportedly lighting fires to block a key road into the city.


The clashes are the most violent yet seen in the Syrian capital, the seat of Bashar al-Assad's regime, but the pro-government newspaper, Al-Watan, has carried a front page headline apparently addressed to activists which read: "You will never take Damascus".


"Al-Midan and Tadamon are out of the army's control," Ahmed al-Khatib, spokesman for the Free Syrian Army's military council in Damascus, said.


"The army has no presence inside either of these neighbourhoods any more, though they are shelling from the outside, and clashes on the edges of the neighbourhoods continue."


Khatib's statements were backed by an activist with the Local Coordination Committees who identified himself as Jacob Hussein.


"This is the beginning of the end," Tadamon-based Mr Hussein said.


"The regime tried to put out the revolt in Damascus by attacking Tadamon. Instead, clashes have spread into several areas of the capital."