The Syrian Observatory for Human Rights said fighting on Wednesday had claimed 104 lives across the country, according to its toll compiled from a network of activists, lawyers and doctors.

In the capital on Thursday, security forces swarmed the southern Zahra district after a car bomb exploded.

The Britain-based Observatory said that according to its initial information no one was killed.

However Syrian state television reported that “Al-Qaeda terrorists exploded a bomb in a car in front of a Red Crescent centre in Damascus, causing one death and major damage.”

Troops loyal to President Bashar al-Assad were shelling three outlying Damascus areas — Douma to the northeast and Daraya and Moadamiyet al-Sham in the southwest.

As the army escalated its bid to seize control of rebel-held Daraya, the scene in August of the single worst massacre in Syria’s 21-month conflict, additional troops were deployed to the town on Thursday.

At the same time, there were clashes in the flashpoint town of Irbin to the east, the monitoring group said.

Damascus province is now a key battlefield, as regime forces battle to retake control of an eight-kilometre (five-mile) belt around the capital.

Elsewhere in Syria, rebels fought against soldiers backed by artillery.

In the embattled northern city of Aleppo, several districts saw clashes, while shells slammed into zones in the southern province of Daraa, according to the Observatory.

It also said explosions rocked the towns of Hama, in central Syria, and Deir Ezzor in the east.

The Observatory has tallied more than 41,000 deaths, most of them civilians, in nearly 21 months of conflict.