Four people were killed in a bomb blast in Beirut's southern suburbs on Tuesday, a security source told Reuters, attributing the attack to a suicide bomber wearing an explosive belt.

The source said another 20 people were wounded in the explosion, which occurred in an area known to be a Hezbollah stronghold.

Meanwhile, AFP reported that the jihadist Al-Nusra Front in Lebanon, believed to be a franchise of the Syrian Al-Qaeda-linked group, claimed responsibility for the attack in retribution against "the massacres carried about by the party of Iran (Hezbollah)" in Syria.

In a statement posted on Al-Nusra Front's Twitter account, the group called the bomb blast a "martyrdom operation in [Hezbollah's] backyard."