As seen in videos posted online, the explosion shattered windows, knocked down doors and shook buildings several hundred feet away.
According to Lebanese media, ambulances were transporting hundreds of injured people to local hospitals and dozens may have been killed in the incident.
The source of the blast which appeared to occur around the Lebanese capital’s port is currently unclear. Cars were left strewn across the surrounding highway. Eyewitnesses told LBC television that at least dozens were hurt and hospitals were full of injured people.
Another driving past the port said he first saw a fire from his window and then felt an enormous explosion that lifted the highway.
Many people were feared to be trapped inside the rubble immediately surrounding the explosion.
Lebanon’s health minister told journalists a ship carrying fireworks had blown up in the port, though the size of the blast heard across the country raised suspicions it might have resulted from a rocket strike or detonation of explosives – deliberate or otherwise. He said at least dozens were wounded but did not give further details of casualties.
An enormous cloud of smoke could be seen from across the city and eyewitnesses said there were reports of a fire and several smaller explosions at the port that preceded the large blast after 6pm on Tuesday.
The office of the Daily Star newspaper about 400 metres from the port was among the buildings to sustain damage from the explosion.
See the explosion video below: