Story highlights Three soldiers are killed in a suicide car bomb attack at a checkpoint

Prime Minister calls it a "repugnant terrorist act."

Hezbollah has also condemned the attack as a terrorist act.

A suicide bomber blew up a booby-trapped car, killing three soldiers and wounding four others at an army checkpoint in Lebanon's Bekaa Valley, according to the National News Agency (NNA).

The army said it has secured the area in Arsal, a town on the Syrian border, and is investigating the Saturday bombing.

Lebanese Prime Minister Tammam Salam condemned the attack on the Army post as "a repugnant terrorist act."

He said: "Operations of the sort will not affect the crucial political decision taken to combat terrorism and all forms of security breach," according to NNA.

Hezbollah, which has a strong presence in the Bekaa Valley and supports the Syrian government in that country's civil war, condemned the bombing.

"This [attack] proves that terrorism is, beyond any doubt, the enemy of all, without exception," it said, according to NNA.

A group operating under the name Free Sunni Brigade in Baalbek claimed responsibility for the attack via Twitter. It claimed responsibility for a suicide attack earlier this month, that was later disputed by a more influential jihadi group.