intelligence chief Wissam al-Hassan was the target
The blast occurred during rush hour, when many parents were picking up children from school, and sent black smoke billowing into the sky.
Eight people were killed and at least 78 were wounded, the state news agency said, quoting civil defense officials.
Several cars were destroyed by the explosion and the front of a multi-story building was badly damaged, with tangled wires and metal railings crashing to the ground.
In the aftermath, residents ran about in panic looking for relatives while others helped carry the wounded to ambulances. Security forces blanketed the area.
Ambulances ferried the wounded to several hospitals, where doctors, nurses and students waited for casualties at the doors. At one hospital, an elderly woman sat in the emergency room with blood staining her blouse.
The hospitals put out an appeal for blood donations.
The war in neighboring Syria, which has killed 30,000 people so far, has pitted mostly Sunni insurgents against President Assad, who is from the Alawite sect linked to Shi’ite Islam.
Tension between Sunnis and Shi’ites has been rumbling in Lebanon ever since the end of the 1975-1990 civil war but reignited after the Syria conflict erupted.
It reached its peak when former Prime Minister Rafik al-Hariri, a Sunni, was killed in 2005. Hariri supporters accused Syria and then Hezbollah of killing him – a charge they both deny. An international tribunal accused several Hezbollah members of involvement in the murder.