Hand-to-hand fighting looms in Isil's Libyan stronghold
Libya rarely makes the headlines these days. With so much happening in Syria and Iraq, the country's turbulent post-Gaddafi transition receives little attention. Now and then, there is a short-lived burst of interest, usually related to the fact that Libya is a transit hub for refugees and migrants trying to get to Europe. Since late 2014, Libya has also made intermittent headlines because Isil saw the troubled country as the most promising of its satellites outside Syria and Iraq.
That may be changing. In recent weeks, Libyan forces - a mix of army units and militias loosely aligned with a months-old UN-backed unity government - have advanced on Isil's stronghold of Sirte, a coastal town in central Libya. Sirte was Gaddafi's birthplace and also where he met his bloody demise at the hands of rebel forces in October 2011.
Fighting continues but the Libyan forces have vowed to rout Isil - which is predominantly comprised of foreigners, including Tunisians, Iraqis, Egyptians and Sudanese - from the city.
Isil took control of Sirte, a city which had been largely abandoned by the post-Gaddafi authorities due to its reputation as a bastion of the former regime, last year.
It consolidated its control through fear and intimidation, carrying out public executions in a bid to cow the local population.
Isil has claimed responsibility for a number of attacks in Libya since late 2014, including one on the five-star Corinthia Hotel in the capital Tripoli last year, in which over a dozen people were killed, and several on oil facilities south of Sirte. It also abducted and later beheaded 21 Egyptian Copts near Sirte. Earlier this year, Isil carried out a suicide truck bombing on a police training centre in the western town of Zliten. More than 60 people were killed in what was Libya's single deadliest attack yet.
Isil first gained a foothold in Derna, a city in eastern Libya. Many young men from Derna had travelled to Syria to join Isil in Syria and Iraq. Some returned home to build its first Libyan affiliate, which declared its allegiance to Isil leader Abu Bakr al-Baghdadi in late 2014.
The group's expansion into Libya was helped by the chaos caused by a political power struggle which began in summer 2014 and led to the country being divided between rival governments and rival parliaments, all backed by a constellation of armed groups.
Isil saw opportunity in the resulting vacuum as the bickering factions were more focused on prevailing over their opponents than acknowledging, let alone addressing, the growing threat posed by the extremist group.
A lengthy UN-led mediation process culminated last December in a deal designed to bring a unity government into existence. This government is currently trying to take shape in Tripoli but faces daunting challenges, including the fact that powerful armed groups in different parts of the country oppose it.
Western powers had hoped this unity government would be the first step in bringing Libya's squabbling factions together to fight Isil but there is little sign of that happening.
The forces that have taken on Isil in Sirte in recent weeks are all from western Libya and largely opposed to armed factions in eastern Libya, who are loyal to a controversial general named Khalifa Haftar. He is against the UN-backed unity government.
The rapid advances made by the forces battling Isil in Sirte - which is 450km from Tripoli - have taken many by surprise.
They managed to seize control of its port and airport early on but their push deeper into the city has slowed over the past week as Isil fighters responded with suicide bombings and snipers.
The weeks-old offensive has so far left 145 anti-Isil fighters dead and 500 injured. Last week, their commanders were claiming that Sirte would fall 'within days' but that was premature. What is likely to unfold is a street-by-street battle in which hardened Isil fighters with nothing to lose put up a fierce fight to hold the city that became their stronghold.
Over the past year, Isil has been driven from its first redoubt in Derna and from the outskirts of the western Libya town of Sabratha.
Losing Sirte would be a blow not just to Isil in Libya but to the parent group in Syria and Iraq.
Libya is the only place outside Syria and Iraq where the group controls territory. It has featured frequently in Isil propaganda, with the group calling on foreign fighters to flock to the country. With Libya just across the Mediterranean from Europe - something Isil has boasted of - the battle in Sirte is not just important for Libyans but also its European neighbours to the north.