The blast shook the capital’s centre, close to the government’s headquarters and parliament, injuring at least 71 people, according to initial medical reports.
Immediate footage showed people fleeing the area of the incident in the residential Ain el Merasa district, with cars ablaze and people on fire, as clouds of black smoke billowed surrounding banks, restaurants and hotels.
Medics and army troops were deployed to the scene where Shattah, a close aide of Saad al Hariri, the country’s former prime minister, was believed to have been targeted as his convoy was passing through. Shattah was also a leading member of the Future Movement.
Al Jazeera’s Rula Amin, reporting from the site of the attack, said security forces have been on the alert for at least 10 days.
Amin added the blast was so strong that even people in the buildings around the area of the bombing were injured as windows shattered.
She also said that Shattah was a very critical vocal of Syrian President Bashar al-Assad’s regime in Syria as well as Hezbollah, the Shia group based in the south of the capital and other areas in Lebanon.
He was also a leading figure in an international tribunal which was formed to look into the the assasination of Rafik al Hariri, the Lebanese former prime minister assasinated in 2005, Amin said.
Al Jazeera’s correspondent added that it was not clear if the bombing was carried out through a suicide attack or any other method.
She also said that Hezbollah condemned the attack.
Beirut has been hit by several deadly attacks over the past months, including twin suicide blasts in November that targeted the Iranian embassy.
The assasination of the Muslim Sunni senior official marks the latest in a spate of attacks that have recently torn the multi-confessional country, fueled by the next-door civil war in Syria.