Three suicide bombers detonated cars packed with explosives in the main square of the northern city of Aleppo yesterday, killing at least 33 people, levelling buildings and trapping survivors under the rubble.
A fourth explosion a few hundred metres away struck near the edge of the Old City, a Unesco World Heritage site that has seen fierce street fighting between rebels and government forces.
There was no immediate claim of responsibility, but the government blamed its opponents and said the blasts were caused by suicide bombers. The bloodshed comes amid growing concerns that extremists such as al-Qa'ida are making inroads inside Syria.
The Syrian opposition denies any links to terrorists, but a Sunni extremist group called Jabhat al-Nusra, or Victory Front, has claimed responsibility for bombings in the past.
Long free of the violence that has engulfed much of the rest of the country, Aleppo in the past two months has become a key battleground between regime forces and rebels trying to oust President Bashar al-Assad. The opposition launched an initial offensive on the city, Syria's largest and a commercial hub, in July. Large swaths of the ancient city have been shattered.