Dozens of people have been injured after a car-bomb ripped through a southern suburb of the Lebanese capital Beirut.

The Bir al-Abed area of Beirut's Dahiyeh suburb is a Hezbollah stronghold, and Hezbollah operatives have already sealed off the area according to Reuters, which apparently occurred at a shopping mall run by the Shi'ite terrorist group.

Hezbollah's Al Manar television broadcast footage from the aftermath of the attack, in which a large cloud of smoke can be seen as bystanders rush to the site of the blast.

Syrian rebel groups have repeatedly threatened to target Hezbollah in Lebanon, due to the Iranian-funded group's active military support for the Assad regime, which proved key in the battle for the strategically-important Quseir region on the Syrian-Lebanese border.

In May, only hours after Hezbollah leader Hassan Nasrallah openly admitted his organisation's role in fighting Syrian rebels - who are mainly Sunni Muslims - two rockets were fired into a Hezbollah-controlled suburb of Beirut, injuring four people.

This latest attack will fuel rising concerns over a potentially devastating sectarian "spill-over" from the Syrian civil war, which has already claimed at least 100,000 lives.

Following the attack, Free Syrian Army commander Louay Almokdad condemned the bombing in an interview with the Lebanese Al Nahar media agency, and accused the Assad regime and Hezbollah chief Hassan Nasrallah as being "directly or indirectly responsible." 

However, the Syrian opposition is not centrally controlled, and suspicious is falling upon the extreme Islamist factions, including those affiliated with Al Qaeda.