Some 4,000 people have been injured, many suffering from moderate to serious wounds, the Lebanese Red Cross said.
Lebanese Red Cross Secretary General George Kettneh told dpa that the death toll could increase.
A civil defence official told dpa they are still searching for around 100 people missing under the rubble, especially in the vicinity of Beirut port.
“There are many people still covered under the rubble,” said the official, who requested anonymity for not having permission to speak to the media.
Lebanon woke up to scenes of massive damage at Beirut’s port and nearby areas in the centre of the capital.
Dozens of damaged cars lined the main highway, apartment buildings were surrounded by shattered glass, and some people slept without windows.
“This is horrific … this is not something usual,” said one man who was sweeping the glass in front of his apartment.
A Lebanese army officer at the scene, who requested anonymity, said there are more casualties still buried inside the port.
Workers started to remove some of the debris to open roads and repair the damage in nearby streets, stretching to the famous Gemayzeh Street, home to most of the city’s pubs and Beirut’s usual bustling nightlife.
The explosion takes place as Lebanon is struggling through its worst economic crisis since the country’s 1975-90 civil war ended.
The cabinet is expected to meet in an emergency meeting on Wednesday after Lebanon’s Higher Defence Council declared Beirut a “disaster” area and recommended a two-week state of emergency.
Authorities are still investigating the cause of the explosion, but the internal security chief said the area was housing highly explosive materials.
Prime Minister Hassan Diab vowed to punish the people responsible for the blasts.
He said it was “unacceptable” that a shipment of approximately 2,750 tons of ammonium nitrate was stored in a warehouse in Beirut’s port for six years without safety measures.
Jordan’s army plans to dispatch a military field hospital, with materials and personnel, to provide medical support to Lebanon. Iraq is also expected to send a plane carrying urgent medical aid. (dpa/NAN)