DAMASCUS: Syrian regime warplanes and troops on Friday blasted away at rebels close to Damascus, the day after a car bomb in a mainly Alawite northern district of the capital killed at least 11 people, a watchdog said.

Fighter-bombers were hitting Duma, northeast of Damascus, and army artillery was shelling the southwestern Daraya neighbourhood which the rebels have led against regime assaults for weeks, the Syrian Observatory for Human Rights (SOHR) said.

Troop reinforcements were being sent to Daraya, the British-based group added.

The offensive was being waged a day after a car bomb in the north Damascus neighbourhood of Massaken Barzeh, mostly inhabited by members of President Bashar al-Assad's Alawite minority, killed at least 11 people, the Observatory said.

Two children were among the dead in the attack, it said.

The official SANA news agency said the bomb struck a petrol station near a hospital and that it also wounded many civilians.

The Syrian Revolution General Commission (SRGC) activist network close to the rebels also reported the attack, adding that large numbers of troops deployed in the neighbourhood afterwards.

On Wednesday, the United Nations said the overall death toll from the 21-month conflict had topped 60,000. The fatality rate has multiplied in recent months, as air strikes have stepped up.

Nationwide on Thursday at least 191 people died, including 99 civilians, according to the Observatory, which gathers information from a network of medics and activists. Fighting in Damascus and its outskirts accounted for 87 of the deaths, it said.

Daraya has become one of the bloodiest battlefields in Syria's civil war.

In August, the district was the scene of the worst massacre of the conflict when more than 500 people were reportedly killed.

Al-Watan, a pro-regime newspaper, claimed on Friday that the army had “won the battle against the terrorists in Daraya and destroyed their last positions”.

It said that several members of the jihadist Al-Nusra Front rebel group had been killed, wounded or surrendered and that Daraya should be fully secured later Friday.

As with many of the claimed victories put out by the regime or the rebels, there was no way of verifying the situation. Many of the supposed triumphs have later turned out to be empty boasts.

Assad's regime routinely describes the insurgents as “terrorists”, claiming many are foreign and backed by money and arms from Gulf Arab states and the West.

The rebels acknowledge a minority of foreign fighters in their ranks, but say their struggle is one of Syrians for a Syria free of Assad. They reject any negotiations as long as Assad remains in power.

The Syrian Observatory for Human Rights said that, of the 51 rebels killed on Thursday, at least five were foreigners – one Palestinian, one Turk, one Saudi and two Libyans.

Australia has warned its nationals they face up to 20 years in jail if caught fighting in Syria, in a foreign ministry announcement made after a Melbourne man was reportedly killed in the conflict.

A ministry spokesman said the Australian government was aware of reports that more than 100 Australians had engaged in the conflict since 2011 but he had “no evidence” of any citizens currently involved.

Lebanon, meanwhile, said it would keep its border open to receive more refugees from Syria, but called on other Arab states and the international community to make good on financial pledges to help it cope with the influx.

The country already has 125,000 refugees from its roiled neighbour, according to UN figures, or 200,000 according to government estimates.