Brig. Gen. Francois Hajj had been set to become the chief of staff if Gen. Michel Suleiman, the current head of Lebanon's military, is elected president of the troubled Middle East country next week.
"This morning, the criminal hand targeted the head of army operations Brig. Gen. Francois Hajj with a bomb as he drove in his car opposite the Baabda municipality, which led to his death along with a number of soldiers, and wounded others," said the military in a statement.
The military's chief of operations, Brig. Gen. Francois Hajj led the army's assault on militants entrenched in the northern Lebanese Palestinian refugee camp of Nahr el-Bared in September this year. Around 400 people died in the subsequent fighting.
Wednesday morning's car bomb attack, which killed at least five people, looks set to exacerbate the already tense political situation in Lebanon.
The country's presidential post has been vacant since November 23, with a divided parliament failing to elect a leader due to disputes between the government and the Hizbollah-led opposition. Presidential elections have been repeatedly postponed, and are now set for December 17.
The attack, the country's majority leader Saad al-Hariri said in a statement, was "a link in the terrorist chain directed at Lebanon and its institutions, foremost among them the national army, which today pays the price for defending Lebanon's sovereignty, independence and free will."
The deadlock has already caused a political turmoil seen by many as the worst in Lebanon since the bloody civil war that tore the country apart from 1975-1990.
"Any delay in the election of the new Lebanese president may have irredeemable consequences," Russia's foreign ministry spokesman said.
Mikhail Kamynin condemned the attack, saying it possessed "a clear provocative nature," and adding that, "it was carried out when Lebanese leaders were close to reaching agreement on a consensus president."
The death of Brig. Gen. Francois Hajj is one of a number of high profile political assassinations to have taken place in Lebanon in the last two years. The vast majority of the victims have been anti-Syrian campaigners.
