A suicide car bomb exploded in the main business district of Damascus on Monday, killing at least 15 people, setting cars ablaze and damaging buildings, according to state television.

A Damascus resident who described the blast as the biggest she had heard in the capital during the two-year-old revolt against President Bashar al-Assad said large plumes of black smoke were rising from the Sabaa Bahrat district.

State television said the explosion had occurred near a school in Sabaa Bahrat, a heavily populated area that also houses the Central Bank and the Finance Ministry. It said 53 people were wounded.

Residents and opposition activists reported hearing gunfire and ambulance sirens in the vicinity. State television said shots had been fired in the air to clear a path for ambulances.

It showed footage of seven bodies in the street, including at least two charred corpses in the wreckage of an overturned bus. The fire brigade was dousing flames from cars crushed by the blast. Other vehicles were still on fire, lined up in what appeared to be a car park.

Men carried away a woman on a stretcher whose face was covered in blood. Panic-stricken women in long black dresses and headscarves ran towards the scene. State television showed some bandaged children in school uniform.

The British-based Syrian Observatory for Human Rights, a monitoring group with a network of local sources, including hospitals, said at least eight people had been killed.

There was no immediate claim of responsibility for the attack, but state media blamed "terrorists", a term the government uses for opposition fighters. Opposition groups accused the government of carrying out the attack.

Syrian insurgents based in the outskirts of Damascus have pushed into areas near the government-held heart of the city, stepping up mortar and car bomb attacks in recent weeks.

More than 70,000 people have been killed in the conflict, which started with peaceful protests against four decades of Assad family rule that were violently suppressed. An armed struggle ensued, forcing more than a million Syrians to flee abroad, and displacing millions more inside the country. – Reuters