At least three people have been killed when a suicide attacker detonated a car bomb at a petrol station in Lebanon's Bekaa valley near the border with Syria, Al Arabiya News reported.
The blast occurred in the small town of Nabi Osmane, a stronghold of the Lebanese Shiite Muslim militant group Hezbollah.
Lebanese media reports say a Hezbollah official was among those killed.
Footage aired on the Hezbollah-owned al-Manar TV channel showed police cordoning off the area of the explosion and the twisted metal of a burnt-out car.
Hezbollah-dominated areas in eastern Lebanon and southern Beirut have witnessed a series of deadly attacks, many of them suicide car blasts.
The attacks have been linked Hezbollah's involvement in the Syrian war to support President Bashar al-Assad's troops in his war against opposition fighters.
The latest attack comes hours after the Syrian army backed by Hezbollah fighters captured Yabrud, a former rebel bastion in Syria near the Lebanese border.
Hezbollah and Lebanese security forces have said many of the car bombs used in previous suicide car bombings originated in Yabrud.
Immediately after news of the attack broke, a radical Sunni Islamist group claimed responsibility for the blast via Twitter.
"Liwa Ahrar al-Sunna in Baalbek officially takes responsibility for the heroic martyrdom (suicide) operation 'revenge for Yabrud' in the village of Al-Nabi Othman," the group said.
It also warned Hezbollah and the Lebanese army -- which radical Sunni groups in Lebanon say has sided with the Shiite movement: "Prepare for the transfer of the battle of Yabrud into Lebanese territory."
Lebanon is deeply divided over the war in neighboring Syria. While Hezbollah and its allies back Assad, many of the country's Sunnis support the three-year revolt.