At least 34 people died when two suicide bombers detonated their explosives-packed vehicles near a cluster of commercial buildings in a suburb of Damascus.
The latest carnage to hit an area of the Syrian capital populated by religious minorities who support President Bashar Assad further raises concerns of a growing Islamic militant element among the forces seeking to topple him.
In the country's north, rebels claimed to have shot down a Syrian air force fighter jet, providing further evidence of their growing effectiveness and improved military capabilities. It was not immediately clear how the MiG-23 was downed, although activists and the Turkish state-run Anadolu news agency said it was probably brought down by a missile.
The morning rush-hour bombings in the Damascus suburb of Jaramana were the latest to hit the overwhelmingly pro-regime town. The twin blasts appeared designed to maximise damage and casualties and bore the hallmarks of radical Muslim groups fighting alongside other rebel units in Syria.
There was no immediate claim of responsibility for the bombings, but Jabhat al-Nusra, an al Qaida-inspired extremist group which has become one of Syria's most potent and organised rebel groups, has claimed numerous suicide bombings in the past, mostly targeting regime forces and security installations.
The bombs went off in a car park near commercial buildings as groups of labourers and employees were arriving for work, killing 34 people and injuring another 83, state-run news agency Sana said.
The blasts sent people fleeing in panic, shattering windows and littering the streets with glass, debris and pools of blood. Several commercial buildings were damaged, and dozens of cars were reduced to smoldering wreckage.