The official said the attack today night occurred in a remote region of Ras Baalbek in eastern Lebanon and was followed by fierce clashes between the two sides. The official spoke on condition of anonymity as he wasn't authorized to speak to journalists.
The state-run National News Agency also reported the ambush, saying there were several soldiers killed and wounded.
It said the Lebanese military called in air support to the area.
It was not immediately clear who was behind the attack.