A suicide bomber detonated an explosives-packed vehicle near a checkpoint and a café in an area south of Lebanon's capital Beirut, causing several casualties.
The explosion occurred just after midnight local time near the Abu Assaf café, where people had gathered to watch World Cup matches.
An Associated Press reporter on the scene said he saw at least two wounded people. The state-run National News Agency said 12 people were wounded.
A security official said the blast near the Shatila area was caused by a suicide car bomb attacker and that at least five people were wounded. The area is a stronghold of the Shiite militant Hezbollah group.
It was the second explosion in a week and comes amid mounting regional tensions over dramatic events in nearby Iraq, where the al-Qa'ida splinter group Islamic State of Iraq and the Levant (Isis)has seized large chunks of territory in the country's north and west.
On Friday, a suicide bomber detonated his explosives-laden car near a police checkpoint in eastern Lebanon, killing a policeman and wounding several other people.
The bombings, coupled with the detention in Beirut of alleged militant sleeping cells on Friday, sparked fears of renewed violence in a country which has been buffeted by the conflict in neighbouring Syria.
Syria's civil war has spilled into neighbouring Lebanon on multiple occasions and inflamed sectarian tensions. A series of car bombs have struck Shiite areas across Lebanon, killing dozens of people.
However, the last explosion to hit Lebanon before Friday's occurred on March 29, when a suicide bomber in an explosives-laden car targeted a Lebanese army checkpoint near the Syrian border, killing three people.
Hard-line Sunni groups have claimed responsibility for the attacks against Shiite areas, saying they are meant to punish the Lebanese Shiite Hezbollah movement for fighting alongside Syrian President Bashar Assad's troops in Syria.
After Friday's bombing, troops began enforcing strict measures at all entrances to Beirut's southern suburbs, a Hezbollah stronghold, setting up checkpoints and searching cars.
The Lebanese are deeply divided over the civil war in Syria, with Sunnis largely backing the insurgency and Shiites siding with Assad.