Forces aligned with Libya's unity government say they have taken control of the port of Sirte, making further gains in Islamic State's North African stronghold.
Brigades largely composed of fighters from Misrata advanced this week to the perimeter of Sirte's city centre, after launching a counter-attack against IS last month and driving the militant group back along the coastal road between the two cities.
The brigades are part of an operation backed by Libya's UN-backed Government of National Accord (GNA), which arrived in Tripoli in March and has been gradually working to establish its authority.
Western powers see it as the best bet for trying to unite Libya's political and armed factions against Islamic State and for restoring stability to the oil-rich North African country.
A source from the operations room in Misrata said fighters from the front line in the south of Sirte had looped around to the seafront to capture the port, about 5km east of the city centre.
The brigades have advanced more swiftly than many expected, though their progress has been hampered by suicide bombers, mines and snipers.
Clashes in Sirte on Friday killed 11 brigade members and wounded 35, the operations room source said. More than 100 fighters from the GNA-backed brigades have been killed and more than 500 wounded since the campaign to recapture Sirte began in early May.
Islamic State started expanding into Libya in 2014 as the political turmoil and conflict in the country worsened. It took control of Sirte last year, but has struggled to retain territory or win support elsewhere in Libya.
As the brigades based in Misrata have advanced on Sirte from the west, a separate force that controls some of Libya's key oil terminals and is also aligned with the GNA has pushed Islamic State back from the east. They reached Harawa, a town about 70km from Sirte, on Thursday.