The Syrian government has appealed to the United Nations for help in combating terrorism, saying that a spate of bombings are proof it is under attack from forces armed by foreign powers.

State media said the regime of Bashar al-Assad called on the UN Security Council and Ban Ki-moon for assistance in tackling the escalating crimes committed by terrorists receiving help from abroad.

The call for aid comes a day after twin car bombs in the capital of Damascus killed at least 55 people and wounded 372, the deadliest attack in Syria since the uprising against Assad began 14 months ago.

Despite the capital city being under the tight control of President Bashar al-Assad's forces, the area has been shaken by several explosions in recent days.

The first explosion on Thursday occurred in the al-Qazzaz district in the south of the city, shortly before 8 a.m. local time.

A second device, much larger than the first and timed to go off as people gathered at the scene of the first blast, then exploded a short time later.

The area is said to house a military intelligence complex.

Arab League peace envoy Kofi Annan condemned the attacks, saying: These abhorrent acts are unacceptable and the violence in Syria must stop.

However, on Friday, the head of Syria's main opposition group blamed the attacks on al-Qaida linked forces which were aided by the government itself.

Speaking in Tokyo, prominent Syrian opposition leader Burhan Ghalioun said Assad was trying to sabotage the shaky ceasefire agreement, brokered by the UN last month.

In the meantime, the head of the UN's observer mission Neeraj Singh said his staff had grown to 150.

You have the world coming together, the world community coming together to be with the people of Syria to see in what way we can help.

The most important thing being that violence in all its forms has to stop, he said, according to Voice of America.

The British-based Syrian Observatory for Human Rights has reported that the total death toll in the country has climbed above 12,000 over the 14-month period of the uprising against Assad.