Fresh fighting meanwhile erupted in several flashpoint areas around the capital, while the army renewed its shelling on besieged rebel areas of the central city of Homs, said the Syrian Observatory for Human Rights.

"Warplanes carried out several air strikes on the edges of Assali (in the south) and Qaboon (east)," said the Britain-based group, referring to areas on the outskirts of Damascus.

The Observatory also reported fresh clashes in Assali as well as in the southwestern neighbourhood of Qadam, adding that the army shelled rebel-held Yarmuk in the south and Jubar in the east.

Air strikes also targeted other rebel areas east of Damascus, among them insurgent bastion Zamalka, said the group.

Violence has encroached deeper into Damascus in the past few months, with several outlying districts battered by shelling and fighting. Central Damascus is still squarely in army hands.