A car bomb on Tuesday rocked Beirut's Hezbollah stronghold in the southern suburbs, which is populated mainly by Shiite Muslims, Lebanese television channels reported.

Several broadcasters, among them Hezbollah's Al-Manar, reported injuries while private channel LBC showed a large cloud of black smoke rising above the densely populated Bir al-Abed neighbourhood.

"The explosion in the Bir al-Abed area was caused by a car bomb in the parking lot next to an Islamic cooperation centre," Al-Manar reported.

Shiite movement Hezbollah has sent fighters to join Syrian President Bashar al-Assad's forces in facing down a revolt, an issue that has deeply divided Lebanon and sparked frequent eruptions of violence.