The bomb attack took place by an explosives-rigged vehicle at the checkpoint about 3 miles (4.8 kilometers) from the Syria border near the town of Khreibeh.
Lebanese security sources have allegedly said that the victims included members of the Lebanese resistance movement Hezbollah.
On Friday, a roadside bomb killed two Lebanese soldiers as the army truck passed by on a road near the town of Arsal on the border with Syria.
Violence erupted in eastern Lebanon after soldiers arrested a Syrian man who the army said confessed to belonging to the ISIL. Angered by the arrest, the Takfiri terrorists opened fire on army checkpoints and stormed a police station in a border area.
Northern Lebanon has been the epicenter of fierce clashes between the supporters and opponents of the Syrian government. The Takfiri terrorists are said to have infiltrated into Lebanon from Syria’s mountainous al-Qalamoun region.
Syria has been gripped by deadly violence since 2011 with the ISIL Takfiri terrorists currently controlling parts of it mostly in the east.