The attack, carried out on Saturday at the entrance to the northeastern town of Hermel, also injured six other people.
The Hezbollah Islamic resistance movement has a strong presence in Hermel.
The latest terrorist incident follows twin suicide bombings of the Iranian cultural center in Beirut that killed 11 people and injured scores of others on Wednesday.
The al-Qaeda-linked Abdullah Azzam Brigades claimed responsibility for the bombings.
It was the second such attack targeting Iranian interests in Lebanon, with the group saying the violence was retribution for the country’s support for Hezbollah, which is assisting Syrian forces in their battles with a massive foreign-sponsored insurgency.
The group also claimed the Nov. 19 bombings of the Iranian Embassy, which is located in the same area.
RA/MB