A member of the Hezbollah militant movement has escaped a bomb attack on his car in eastern Lebanon.
Hezbollah has vowed revenge against Israel
The explosion happened in the Hezbollah stronghold of Baalbek, near the Syrian border, but caused no casualties, police have said.
The Hezbollah official had got out of the car moments before the blast, reports have said.
Hezbollah blamed Israel for a "treacherous assassination attempt". Israel denied it was behind the blast.
"The Zionist enemy is fully responsible for the operation's planning and execution," Hezbollah said in a statement broadcast on its al-Manar Television.
"The Islamic resistance will fully shoulder its responsibility in this regard and do what is necessary," it went on.
Israeli warplanes recently bombed southern Lebanon following attacks on Israeli army posts by Hezbollah - a Lebanon-based Shia Muslim movement.
Friday's blast took place outside the house of senior Hezbollah leader Sheikh Mohammad Yazbek, who sits on the movement's Shoura Council - its top decision-making authority.
The man who got out of the car was named as Hussein Assaf - an official the police said was in charge of training Hezbollah guerrillas - who was at the house for a meeting.
The historic town of Baalbek is known for its Roman temples, but also for being a base for Hezbollah, says the BBC's Kim Ghattas in Beirut.
There have been a series of mysterious bombings in Lebanon in recent months, she adds.
The most notable killed former Prime Minister Rafik Hariri and 22 other people in Beirut in February, and is the subject of a UN investigation.
Many of the targets have been figures opposed to Syria's dominant role in Lebanon.
Hezbollah, however, is pro-Syrian.