Spiritual Leader of Libya's Biggest Jihadi Group Pledges Allegiance to ISIS

Ansar al-Sharia, the top jihadi group in the civil war-torn country of Libya, has edged closer to pledging allegiance to ISIS after its spiritual leader and top judge, Abu Abdullah al-Libi, defected to the radical group, according to an audio message released by the terror group.

On Sunday, al-Libi - who was Ansar al-Sharia's Shari'i (or judge) - confirmed his departure from the jihadi group when he tweeted a picture of a book entitled The Legal Validity of Pledging Allegiance to the Islamic State, along with the caption "Soon, God willing".

In an audio message released on ISIS-controlled radio in the central Libyan city of Sirte last week, ISIS accepted al-Libi's pledge of allegiance to the group's caliph Abu Bakr al-Baghdadi.

"We start with the news that will soften the hearts of the believers [out of joy] in Benghazi, where the Caliphate have accepted the pledge of allegiance of Shaykh Abu Abdullah Al-Libi to the caliph, Abu Bakr - with great happiness, and we ask Allah to bless his pledge and make it a source of Kheyr [good] in the building/progress of the caliphate," the statement says, as translated by researcher The Maghrebi Note.

Analysts have noted that since the death of Ansar al-Sharia's pro-al-Qaeda leader Mohamed al-Zehawi in clashes last year, the group have shown signs of moving closer to the tactics of ISIS. Zehawi was opposed to building state institutions but, following his death, the group have started to build them, a tactic also employed by Islamic State.

Michael Horowitz, senior analyst at the geopolitical risk consultancy Max Security Solutions, predicts that, after al-Libi's defection to ISIS, a pledge of allegiance from Ansar al-Sharia to ISIS is just months away, a move which would make ISIS the biggest jihadi group in the country.

"What it means is that he is trying to convince the rest of the group to pledge allegiance to IS. It's very significant," he says. "A pledge of allegiance by Ansar al-Sharia would mean that the Islamic State would become the most prominent jihadi group in Libya."

"The fact that the judge of the group has pledged allegiance to IS is a big weight in the balance. It's a matter of time," Horowitz adds. "In the coming months there is probably going to be a pledge of allegiance but it is difficult to estimate exactly when because they have no leader."

In the eastern Libyan city of Benghazi, where both ISIS and Ansar al-Sharia have been battling the forces of Libyan general Khalifa Haftar, the group have implemented sharia courts and an Islamic police force.

Last January, the United States designated the group as a terrorist organisation and has claimed that they were responsible for the deadly raid on the U.S. consulate in Benghazi in 2012, in which the U.S. ambassador to Libya and three other American nationals were killed.

Libya is currently divided between two rival factions in its western and eastern regions following the removal of Colonel Muammar Gaddafi in 2011 by rebels backed by a coalition including France, Britain, United States and Italy.

The power vacuum in Libya has allowed rival jihadi groups, especially ISIS, to proliferate, with the group controlling the coastal town of Derna in the country's east and capturing key areas in the central city of Sirte.

One faction is linked to the internationally-recognised government in the east, which is based in the city of Tobruk, and the other is allied to the Islamist-backed Fajr Libya (Libya Dawn) who took control of Tripoli last summer.