Lebanese state media report a massive car bomb exploded in Beirut on Friday, killing at least eight people and injuring some 80 others.

Citing security sources, media reports said a car parked in the center of the capital suddenly erupted into flames during rush hour.

Among those killed was Wissam al-Hassan, the head of a Lebanese intelligence agency. Al-Hassan had been looking into the involvement of Syria and Hezbollah in the assassination of former Lebanese Prime Minister Rafik al-Hariri in 2005.

Officials have yet to find out who was behind the car bombing, but authorities are focusing their investigation on Syria as al-Hassan had opposed the Syrian government. Authorities are also looking into whether the Shiites in the country are responsible.