A suicide car bomb blast has exploded near a Hezbollah base in eastern Lebanon in the latest deadly attack to target the Shia militant group's interests in the country.

The Lebanese National News Agency said the bomber detonated his vehicle in the remote area of eastern Bekaa Valley near the village of Sbouba in the Baalbek region, roughly one mile from a base belonging to the Iranian-backed group.

The report said the explosion caused an unspecified number of casualties among Hezbollah members and civilians.

The bombing appeared to be related to a series of reprisal attacks over Hezbollah's role in the civil war in neighbouring Syria, where fighters from the group are fighting alongside president Bashar Assad's troops. The group has received threats of retaliation from the largely Sunni rebels fighting to topple him.

Hezbollah's Al-Manar TV confirmed the blast took place near one of the group's bases, but said there were no casualties. It did not provide further information. A Lebanese security official confirmed the explosion but said there was no immediate word on the nature of the target or casualties.

Footage aired on Lebanese television channels showed several badly damaged vehicles, including the charred wreckage of an overturned vehicle.

The report said that the explosion took place on the road between Sbouba and Wadi Abu Mousa.

It first said the car bomb was "intercepted" at a Hezbollah checkpoint and exploded after members of the checkpoint fired on it.

It was unclear if the car detonated from the gunshots or if the driver set off the explosion. Later, the NNA said a suicide bomber had caused multiple casualties, adding that ambulances rushed to the area, which was sealed off by the militant group and, later, the army.

Hezbollah's participation in the civil war in Syria is highly divisive and unpopular in Lebanon, where many feel it has deviated from its original purpose of fighting Israel and that it has exposed the Shia community to retaliation.

The group's open support of Mr Assad has enraged Sunnis - both in Syria and in Lebanon - and left it with no shortage of enemies eager to strike at its strongholds and leadership.

Dozens of people have been killed in deadly car bombings claimed by radical Sunni groups in Lebanon. On December 4, gunmen assassinated a senior Hezbollah commander, Hassan al-Laqees, in the garage of his building in southern Beirut.

And last month, two suicide bombers blew themselves up outside the Iranian Embassy in Beirut, killing 23 people. An al-Qaida-affiliated group claimed responsibility, saying it was payback for Hezbollah's support of Mr Assad's regime.

Hezbollah has been instrumental in helping Mr Assad's forces seize opposition held areas, particularly in areas along the border with Lebanon and near Damascus.