The vehicle containing the bomb exploded after midnight in a car park, gouging out a crater and devastating the ground and first floors of an adjacent apartment block.
Lebanon has been rocked by political turmoil since February 14th when former Prime Minister Rafik al-Hariri was killed in a car bombing, which many Lebanese blame on Syria.
Damascus denies the charge, but the assassination has prompted mass public protests against Syria’s military and political influence in Lebanon.
Faced with mounting international pressure, particularly from President Bush, Syria has begun pulling its troops out of its tiny neighbour after a three decade presence and its intervention in the 1975-1990 civil war.
Many analysts and politicians warn strains are evident in the precarious political, religious and communal balance achieved since Lebanon’s civil war. They say political tensions could spill into violence.
Leading United Nations envoy Terje Roed-Larsen, who has been involved in negotiations with Lebanon and Syria, said on Friday he was worried another leading Lebanese figure could be killed unless there was a cooling off period in the country.
Maronite Christians, about one-fifth of the population and long Syria’s most vocal opponents, have dominated the past few weeks’ protests demanding the withdrawal of Syrian troops.
Christian opposition leader Michel Aoun said on Friday he hoped to end 14 years of exile and return to Lebanon within weeks, as soon as the Syrians had completed their withdrawal.
Syria finished the first phase of its pullout on Thursday.
A Lebanese security source said 4,000 to 6,000 Syrian troops had returned home since the pullout plan was announced on March 5, leaving 8,000 to 10,000 in eastern Lebanon.
UN Secretary-General Kofi Annan expects Syria to fully withdraw its forces before Lebanese elections due in May.
Deepening Lebanon’s political crisis, key opposition leader Walid Jumblatt has said he and his allies will not join a government as long as pro-Syrian President Emile Lahoud remains in office.
That stance could wreck a bid to forge a unity government by pro-Syrian Prime Minister Omar Karami, who resigned on February 28 under opposition pressure but was reappointed last week.