General Khalifa Haftar's self-proclaimed Libyan National Army said Wednesday it was tightening the noose on the last jihadist bastion in the country's east after breaking through the suburbs of Derna.
Haftar launched an offensive on May 7 to "liberate" the eastern coastal city, home to about 150,000 people and held by hardline fighters since the fall of Moamer Kadhafi in 2011.
"Army forces are steadily advancing on Derna to liberate it from the grip of terrorist groups," LNA spokesman General Ahmad al-Mesmari told AFP.
The LNA carried out "combat missions" and took control of fortified positions at the entrances of the city, he said.
On Tuesday, the spokesman announced the death of the head of an LNA special forces unit, without specifying whether there had been other losses among Haftar's forces since the offensive began.
"The enemy has suffered heavy losses in terms of men and equipment," he added.
In a speech late Tuesday, Haftar said the LNA was "near victory", calling on his forces to protect civilians and their property and to treat prisoners well.
"We are close... to liberating our country from the last bastion of terrorism," he said.
Rights groups, including Human Rights Watch, have expressed concern over risks to civilians in Derna.
LNA forces have besieged the city for nearly two years, making it difficult for residents to access humanitarian aid.
Derna is held by a ragtag coalition of Islamist and jihadist militias, including groups close to Al-Qaeda, hostile to both Haftar and the Islamic State group.
Libya has been wracked by chaos since a 2011 uprising that toppled and killed long-time dictator Kadhafi, with two rival authorities vying for control.
Haftar supports an administration based in the east of the country. A UN-backed unity government based in the capital Tripoli has struggled to assert its authority outside the west.
The stronghold of hardline fighters Derna, 1,000 kilometres (620 miles), is the only area in the country's east not controlled by Haftar's forces.