Forces loyal to the Libyan unity government say they have retaken the port area in the city of Sirte from the Islamic State (Isis) as street battles rage on. The unity forces, largely compromising of fighters from Misrata advanced rapidly this week to the perimeter of Sirte's city centre where a weaker-than-expected Daesh (Isis) defence has fallen quickly.

Fierce fighting with militants from IS continues in the city as the jihadis' coastal bastion looks set to fall in the coming weeks. The counter attack against the extremists began last month driving the militant group back inside the city with the jihadists now surrounded from three sides.

The forces, aligned to the UN-backed unity government in Tripoli, have now said they have looped around the seafront, roughly 5km (3m), from the city centre in an attempt to encircle Sirte. Fighting in the city on Friday 10 June left 11 brigade members dead and 35 wounded as the Libyan forces contend with suicide bombers, mines and snipers.

The loss of Sirte, the hometown of former dictator Muammar Gaddafi, would be a major blow to IS at a time when it is under pressure in both Syria and Iraq with no large base left in the North African country. Air and missile strikes have hit IS positions this week in the city – which is the most significant IS stronghold outside Iraq and Syria.

The heaviest fighting was said to have taken place near the Ougadougou conference centre which was a venue for international summits and now an IS command centre. IS fighters were said to have responded with sniper fire, machine guns and mortar rounds.

Sirte was the hometown of ousted ruler Muammar Gadaffi and has been the scene of much unrest since his demise in 2011. The unity government, formed in Tripoli, more than two months ago is under pressure from the west to secure the city – which is thought could be a springboard for attacks in Europe.

Both British and US special forces are advising and possibly training government forces in recent months, with French and Italian troops also suspected in taking part. IS began expanding into Libya in 2014 taking full control of Sirte last year along with several other cities on the Mediterranean coast.

Sirte attack
Fighters from forces aligned with Libya's new unity government are seen stationed behind the barricade as they advance on Sirte, June 10, 2016.REUTERS/Stringer