Unconfirmed reports says a second bomb may also have exploded from inside an empty former luxury hotel. Dozens of vehicles were set on fire by the explosion and rubble was strewn across Beirut's coastal boulevard.
Passersby could be seen pulling people on fire from their burning vehicles. Chunks of concrete and shattered glass fell from buildings blocks away due to the force of the explosion and a large plume of black smoke floated over parts of the city.
Former Prime Minister Hariri, who left office in October, had recently become a vocal opponent of Syria's military presence in Lebanon. He joined calls by the opposition for the 14,000 Syrian troops in Lebanon to leave the country before the general election in May.
Syrian President Bashar al Assad quickly condemned the assassination, calling it a "terrible criminal act." Ordinary citizens congregated around the former prime minister's residence, shouting, screaming and expressing their bereavement.