A huge explosion in central Beirut has killed former Lebanese Finance Minister Mohamad Chatah.
He was an adviser to the former Prime Minister Saad Hariri, a Sunni Muslim. A car was seen in flames near government offices and the parliament.
The Syrian conflict has increased sectarian tensions in Lebanon.
The Lebanese Shia militant movement Hezbollah has sent fighters to Syria to back the government of President Bashar al-Assad.
President Assad comes from the Alawite sect, a heterodox offshoot of Shia Islam.