Libyan forces said on Tuesday they had taken one of the last districts in central Sirte held by DAESH, battling snipers and car bombs in their campaign to recapture the entire city.
Forces aligned with Libya's UN-backed government in Tripoli are three months into a campaign to oust DAESH from their former North African stronghold and have encircled the terrorists in a shrinking section of the city centre.
Since August 1, their progress has been aided by US air strikes on DAESH vehicles, weapons and fighting positions. The US Africa Command said it had carried out a total of 48 strikes as of Sunday.
The Libyan forces are composed mainly of brigades from the western city of Misrata.
After they secured key sites south of central Sirte last week, fighting shifted into District 2, which the brigades said they had now captured.
"On Tuesday morning clashes erupted ... that led successfully to the recapture of District 2 with the cooperation of a tank unit to confront DAESH snipers," said Rida Issa, a spokesman for the forces.
"The district is now completely under control of our forces," he said, adding that his side had also made incursions into District 1, situated in the heart of Sirte, the hometown of former Libyan dictator Muammar Gaddafi.
The Misrata-led forces had faced four vehicle-borne bombs, two of which they had destroyed on the ground before they could reach their targets, Issa said.
"One unfortunately exploded near our forces but there are no casualty figures, and the fourth one was bombed by a warplane. We do not know whether it was US air strike or our air defense."
The government-backed forces have been carrying out their own, regular air strikes over the Mediterranean coastal city with a fleet of ageing fighter jets.
At least eight combatants from those forces had been killed and more than 80 wounded in Tuesday's clashes, according to Akram Gliwan, a spokesman at Misrata's central hospital. Some were hit by the car bomb, others by snipers and land mines, Gliwan said.
Officials said on Sunday that only a single residential area, named District 1, remained under full DAESH control, while fighting was ongoing in Districts 2 and 3.
DAESH seized control of Sirte last year, turning it into a base for Libyan and foreign terrorists and extending its control over about 250 km of Libya's Mediterranean coastline.
But it has struggled to win broad support or retain territory in Libya, and losing Sirte will be a major setback for the terrorist group, which has already lost ground to US-backed military campaigns in Iraq and Syria.
Almost all Sirte's estimated population of 80,000 fled after DAESH imposed its rule on the city to escape fighting of the past three months.
Even though Libyan pro-government forces have cornered DAESH in a few pockets of Sirte, analysts says defeat there will be far from the end of the terrorist group in Libya.
"DAESH has lost Sirte, but it has not lost Libya," said Abdelbari Atwan, a journalist and expert on terrorist groups.
The loss of its main stronghold could prompt the group to launch more scattered attacks across the country, which remains an important recruitment base for DAESH.
The latest defeat would probably prompt the terrorist group to change tactics, said Ethan Chorin, an American former diplomat in Libya and head of Perim Associates, a consultancy.
Libya will "very likely see a shift in DAESH strategy to a more diffuse and intensified campaign of terror and intimidation," he told AFP.
"DAESH and like-minded terrorists have consistently shown an ability to 'melt away' at will," Chorin said.
It is hard to estimate the number of DAESH terrorists still alive in Sirte. The Pentagon estimates that they number in the hundreds.
According to French and American sources, a further 5,000-7,000 are present across Libya.
While the loss of Sirte would deprive them of a strategically valuable port, they could move to set up a base in the lawless deserts of southern Libya.
"It is a porous region, as the central state has no presence there and no single militia dominates," said Atwan.
He noted that several major tribes which supported the toppled regime of former dictator Muammar Gaddafi are marginalised today, spurring some of their young men to join DAESH.
"Those people found a refuge in DAESH," he said.