At least 14 people died as a result of the bomb attack, Syrian state television reported on Tuesday, with a further 31 people injured.

"Two suicide bombers attacked Marjeh square causing casualties and material damage," the official television channel Ikhbariya said, as initial news of the attack filtered out.

The channel showed images of broken shop fronts and mangled cars in the city's central Marjeh Square. Ambulance workers were seen carrying wounded individuals on stretchers.

Both state television and the Britain-based Syrian Observatory for Human Rights, which relies on a network of activists, doctors and lawyers for its reports, had initially put the death toll at two.

Ikhbariya said that the two bombings had been carried out by "terrorists" close to a police station in the square. Meanwhile, the Observatory - which later put the death toll at 15 - said that one of the explosions had been inside the police station.

"The number of casualties is expected to rise because several of the wounded are in critical condition," the Observatory added.

There have been frequent bomb attacks in parts of Damascus during Syria's 26-month war, with most of the attacks subsequently being claimed by the jihadist al Nusra front.

The twin explosions are the first in Damascus since troops loyal to Syrian President Bashar al-Assad captured the strategic town of Qusair in Homs province.

Qusair was seen as important for government troops because it linked the capital with government loyalist areas on the coast, while for the rebels it had been on an important supply route from Lebanon.

Both Syrian state-run media and the Hezbollah-owned Al-Manar TV claim the regime is getting ready for an offensive - reportedly named Operation Northern Storm - to recapture Aleppo from rebels. Regime troops are also believed to be advancing towards the central city of Homs.

rc/ipj (AFP, AP, dpa)