Lebanese authorities have arrested a key Syrian commander in the Islamic State.

According to Lebanon's state-run National News Agency, the Army arrested key ISIS commander Hassan Ghorli, also known as Abu Hareth al-Ansari, on March 2 for "for involvement in attacks against army posts in the highlands of Arsal last August, and Tallit el-Hamra and Ras Baalbek in February,when he got injured."

The Lebanese Army carried out successful pre-emptive attacks against jihadist positions on the outskirts of Ras Baalbek last Thursday. The attack resulted in the expulsion of jihadists from two hilltop positions near the town.

Ghorli was being treated for injuries in the Al-Manar Hospital in Hasbaya, in west Bekaa, when he was arrested.

According to the Army, Ghorli was a key figure in August's fighting in Arsal following the Lebanese Army's arrest of Imad Jomaa. Ghorli also confessed during interrogation that he and his group had pledged allegiance to the Islamic State in July.

Imad Jomaa previously led the Fajr al-Islam Brigades, which are affiliated with ISIS, but was arrested by Lebanese authorities in early August last year. His arrest subsequently led to hostilities in Arsal between the Lebanese Army and militants affiliated with the al-Nusra Front and ISIS.

Al-Nusra Front is a separate militant group in Syria that rejected a merger with ISIS in April 2013, choosing instead to align with al-Qaeda, now commanded by Ayman al-Zawahiri. Al-Nusra Front is headed by Abu Mohammad al-Julani.

Ghorli has been transferred to judicial authorities for further questioning, the Army's statement concluded.

According to Lebanese newspaper Daily Star a source within the Syrian rebels said that Ghorli's group is affiliated with al-Nusra Front and not the Islamic State. The source also said that Ghorli was critically injured during a battle in February 23 between Nusra Front militants and Islamic State fighters on the outskirts of Ras Baalbek.