The Friday blast left at least five people dead and dozens injured.
Former Finance Minister Mohammad Chatah was among the victims of the bombing.
Chatah had served as adviser to former prime minister Fuad Siniora and his successor and ex-premier Saad Hariri, whose own father was assassinated in a huge Beirut seafront car bomb in February 2005.
Ambulances and Civil Defense teams rushed to the scene of the explosion between Starco building and Monroe Hotel, a security source said.
The explosion coincided with a March 14 coalition meeting which was expected to take place at former Prime Minister Saad Hariri's residence.
No group has yet claimed responsibility for the attack.
On November 19, around 25 people were killed in a double bomb attack outside the Iranian embassy in Beirut.
BA/BA