Dozens were killed Wednesday when Syrian rebels set off a powerful tunnel explosion targeting an intelligence headquarters in Aleppo and clashed with regime forces, a monitor said.
The Syrian Observatory for Human Rights said the blast hit a building housing the air force intelligence offices in Syria's second city and was followed by heavy clashes. "The explosion and the fighting caused dozens of deaths on both sides," it said.
A Syrian military source confirmed the explosion and said the clashes were ongoing.