A top Lebanese army general was among at least four people killed on Wednesday in a car bombing targeting the military in a Christian suburb on the outskirts of Beirut, a security official told AFP.
The army said Brigadier General Francois El-Hajj, 54, its chief of operations, was killed in the explosion along with a number of soldiers as his car drove past the Baabda municipality during the morning rush-hour.
The security official said at least four people died and up to 10 were injured. The Lebanese Red Cross said five people were hospitalized, none of them with serious wounds.
Several officials said Hajj was targeted as he was tipped to replace as army chief General Michel Sleiman, the frontrunner to become Lebanon's next president but whose election has been blocked by a standoff between pro- and anti-Syrian camps.
An army officer who did not wish to be named said Wednesday's blast was caused by a car bomb that detonated shortly after 7:00 a.m. (0500 GMT) as the general drove by on his way to the defence ministry nearby.
Hajj's body and that of at least another victim were thrown into a nearby ravine by the force of the blast, which blew out the windows of nearby buildings.
Ambulances rushed to the site to evacuate the casualties and firefighters extinguished cars set ablaze, as police and army vehicles cordoned off the area.
"Let me through, let me through, I want to find my father," one woman cried out as police kept her at bay.
A bearded man wearing a navy blue baseball cap and a beige overcoat was seen being detained by the army at the site of the blast but it was not clear whether he was involved in the attack.
Hajj gained prominence last summer during a fierce 15-week battle between the army and an Al-Qaeda-inspired Islamist group at a Palestinian refugee camp in northern Lebanon.
Several officials said his assassination was linked to the battle at Nahr al-Bared camp and the current crisis over the presidency.
"My first reaction is that this is linked to Nahr al-Bared, that it is a revenge attack," said Butros Harb, an MP with the ruling Western-backed majority.
"But I am not sure that this is not also a message to the army in order to destabilise it and remove the halo around it at a time when the commander in chief has been tipped to become president," he added.
Lebanon has been without a president since November 23 when the incumbent Emile Lahoud ended his term and left his seat vacant as feuding politicians bickered over his successor.
On Tuesday a parliament session to elect Sleiman president was postponed for the eighth time, amid a tug-of-war between politicians over how to amend the constitution to allow him to take up the post.
Rival parties have also been at loggerheads over the make-up of the new cabinet and who would be appointed to sensitive top security posts, including that of army chief.
Wednesday's blast came amid high tension in Lebanon which has been rocked by a number of political assassinations in the past two years that have killed eight anti-Syrian MPs and politicians.
One of the slain MPs, Gibran Tueni, died in a car bomb attack exactly two years ago, on December 12, 2005.
The attacks, which began with the February 2005 killing of former prime minister, Rafiq Hariri, have been widely blamed on Syria, which has denied involvement.
The current political crisis is Lebanon's worst since the end of the 1975-1990 civil and there has been fear that it could spill out into violence.