The army on Monday retaliated to shelling from the Islamic State group on the border with Syria after destroying a post for al-Nusra Front in the outskirts of the northeastern border town of Arsal, state-run National News Agency reported.

“Army posts in Ras Baalbek have come under mortar fire from the militants of the IS group who are stationed in the eastern outskirts and the army has responded forcefully,” NNA said.

Al-Jadeed television said the army was using heavy artillery in its bombardment.

Earlier in the day, NNA said the army's Fifth Intervention Regiment had destroyed a Nusra Front post in the Dahr al-Safa area in Arsal's outskirts.

Militants from IS and al-Nusra are entrenched in rugged areas along the undemarcated Lebanese-Syrian border and the army regularly shells their posts while Hizbullah and the Syrian army have engaged in clashes with them on the Syrian side of the border.

The two groups briefly overran the town of Arsal in August 2014 before being ousted by the army after days of deadly battles.

The retreating militants abducted more than 30 troops and policemen of whom four have been executed and nine remain in the captivity of the IS group.