A car bomb has killed at least five people in Hezbollah's stronghold in southern Beirut, the latest in a series of deadly attacks on Shia and Sunni targets in Lebanon.

Several other cars were destroyed by the force of the blast, the blackened and twisted wreckage smouldering on the street in front of buildings whose facades were torn off by the explosion.

Health Minister Ali Hassan Khalil said five people were killed and 66 wounded. A security source said the blast was caused by a car bomb.            

People at the scene said that in addition to the five confirmed dead, the charred remains of a body was found at the scene.

A security source, who spoke on condition of anonymity, said the body was that of a suicide bomber.           

The explosion occurred less than a week after former finance minister Mohamad Chatah, a critic of the Shia Hezbollah militant group and its ally Syrian President Bashar al-Assad, was killed along with six others by a car bomb in Beirut.

Last summer, bombs exploded in southern Beirut and outside two Sunni Muslim mosques in the northern city of Tripoli, killing scores of people.

Bombers also struck the embassy of Hezbollah's Iranian backers in southern Beirut in November.

The violence has been fuelled by sectarian tensions over the conflict in neighbouring Syria, where Assad is fighting Sunni Muslim rebels battling to overthrow him.     

Hezbollah has sent fighters to join Assad's forces, while Lebanese Sunni Muslim fighters have supported the rebels.