A powerful car bomb on Friday rocked a street adjacent to Sassine Square in Ashrafiyeh, leaving eight people dead, including Brigadier General Wissam al-Hasan, chief of the Intelligence Bureau of the Internal Security Forces.

Seventy-eight people were wounded in the first such attack in the Lebanese capital since 2008, according to state-run National News Agency.

The booby-trapped car was parked outside a five-story building facing al-Farah Library, around 200 meters from the Phalange Party's Central House, NNA said.

An Agence France Presse photographer saw two apartment buildings devastated by the bombing. One building was ablaze as Red Cross workers evacuated bloodied casualties.

Balconies were torn off by the force of the blast, windows shattered and cars crushed by falling masonry.

Flying glass from the shattered windows wounded more than 20 people inside their apartments, NNA said.

The agency noted that the blast did not target the convoy of a political figure.

"We heard a powerful explosion. The earth shook under our feet," said Roland, 19, among a large crowd of army, rescue workers and onlookers at the scene.

Interior Minister Marwan Charbel later arrived on the scene to inspect the explosion's aftermath.

Georges Kettaneh, in charge of the Red Cross operation, said at least 37 people were wounded.

Relatives of employees at BEMO bank, whose windows were broken, dashed to the area to look for their children. "Where is Pierre?" one man cried, as a young woman searched for her mother in the rubble.

Nancy, aged 45, was in tears as she reflected on having nearly missed death.

"I was just coming home when I saw my house in flames. I would have been dead if I had stayed home."

A rescue worker, identifying himself as Rahmeh, said "this reminds me of attacks during the (1975-1990) civil war and after the war."

Prime Minister Najib Miqati said "the government and all its security and judicial authorities are on alert to unveil the circumstances of this blast, pursue and punish the perpetrators, and foil any attempts to drag Lebanon back to the episode of bombings."

Miqati also declared Saturday a day of national mourning and ordered the closure of state institutes, the lowering of flags to half-mast and the modification of TV and radio programming.

An extraordinary security meeting was also held at the Grand Serail to discuss the attack, while cabinet was expected to convene on Saturday morning to address the situation.