A suicide bomber blew up his car in southern Beirut on Monday night near an army checkpoint, killing himself and wounding several people watching the soccer World Cup in a nearby cafe.
The bombing came just three days after a failed attempt to kill one of the top security officials in Lebanon, which has suffered a wave of sectarian violence linked to the civil war in neighbouring Syria.
Monday's explosion, shortly before midnight (2100 GMT), killed the bomber and wounded 19 people, Lebanon's civil defence force said. An emergency worker at the nearby Sahel hospital said it treated 11 lightly wounded people.
Reuters television footage from the scene showed the blackened wreckage of a car, surrounded by damaged vehicles.
Windows in nearby buildings were shattered by the blast, which occurred in a mainly Shi'ite Muslim district of southern Beirut inhabited by supporters of the Shi'ite group Amal, an ally of the militant movement Hezbollah.
Hezbollah has been fighting alongside President Bashar al-Assad's forces in Syria against the mainly Sunni Muslim rebels, who have also been supported by Lebanese Sunnis.
The conflict has spilled over into sectarian violence in Lebanon, with rocket attacks on Shi'ite towns in the Bekaa Valley, close to the border with Syria, and bombings of Shi'ite and Sunni targets in Lebanon's main coastal cities.
Security forces have been on high alert since a suicide bomber killed one person and wounded 37 near the Syrian border on Friday in an attack that narrowly missed Major General Abbas Ibrahim, head of Lebanon's General Security department.
The latest violence in Lebanon comes after Sunni insurgents including the Islamic State in Iraq and the Levant (ISIL) swept through north and west Iraq and pushing towards the Shi'ite-led government in Baghdad.
"What is happening in Iraq isn't far from what is happening in Lebanon, but Lebanon will not let ISIL spread here," Hezbollah parliamentarian Ali Ammar told Al-Manar television.
One security source said before Monday night's explosion that security forces were hunting for two potential suicide bombers in the Lebanese capital.