However, there were conflicting reports on the source of the pre-dawn explosion and the number of casualties resulting from the blast in the remote, scarcely inhabited area was not immediately clear.
Hezbollah agents cleared the open field around the area and sealed it off for hours following the blast, making it difficult to establish what had happened.
Hours after the attack, at least four badly damaged vehicles, including the charred, twisted wreckage of an overturned jeep, lay strewn across the rocky field, where spots of blood mixed with patches of snow.
Later today, three rockets hit just outside the northeastern region of Hermel, also a Hezbollah stronghold, without causing any damage, residents said.
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The bombing appeared to be related to a series of reprisal attacks over Hezbollah's role in the civil war in neighbouring Syria, where members of the group are fighting alongside President Bashar Assad's troops. It has received threats of retaliation from the largely Sunni rebels fighting to topple Assad, and Sunni extremist groups have claimed responsibility for bombings in the past few months that have killed dozens.
A Lebanese army statement and Hezbollah's Al-Manar TV station said the explosion was a car bomb, with Al-Manar saying the blast caused an unspecified number of casualties near a "rotation outpost" for Hezbollah fighters.
The station said a Hezbollah convoy of five cars was headed to the base when the group spotted a vehicle parked nearby and grew suspicious. They said several people were killed when they got out of their cars and the vehicle was detonated remotely.