Fierce clashes raged in Benghazi on Friday, leaving more than 20 people dead, on the third day of an offensive by pro-government forces to recapture Libya's second city from Islamist militias.
An AFP correspondent said the latest fighting was the most violent since forces of former general Khalifa Haftar launched the assault on Wednesday with the backing of army units and civilians who have taken up arms.
Benghazi Medical Centre said the 18 dead were mostly soldiers and their civilian supporters in the central district of Al-Majouri.
There was no word on casualties on the side of the Islamists, who rarely announce their losses.
Another four people died on Friday night after a suicide bomber blew up his car at a checkpoint in the central Benghazi district of Boudhima. The suicide bomber was among the dead, Benghazi Medical Centre said.
In a statement on a pro-Haftar television station, Al-Karama, the retired general said he was "satisfied with the results of the battle for Benghazi" and vowed that "victory is near".
At least 52 people have been killed in the three days of what Haftar has called an operation to "liberate" Benghazi, according to hospital figures.
Al-Majouri is home to Mohamed al-Zehawi, leader of the Ansar al-Sharia jihadist group, which the United States has designated a terrorist organisation, and many of his men.
Residents said the two sides were using weapons of all calibres in street fighting in a densely-populated district.
The Libyan Red Crescent called on its Facebook page for a ceasefire, "even for one hour," to allow families to flee the combat zone.
Elsewhere, air raids struck Islamist targets in the districts of Al-Lithi, Al-Massaken and Bouatni, southeast of the Mediterranean city, witnesses said.
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Islamist militias have seized control of large parts of turmoil-gripped Libya since a 2011 uprising against long-time leader Moamer Kadhafi.
The army has this time publicly thrown its weight behind Haftar, who launched a first, unsuccessful, campaign against the Islamists in Benghazi in May, dubbing it "Operation Dignity".
"The Libyan army claims 'Operation Dignity'" as one of its own campaigns, spokesman Colonel Ahmed al-Mesmari said Wednesday.
- Final redoubt -
Before this week's assault, Haftar's forces had been steadily beaten back to a final redoubt at Benghazi's airport, which has come under attack by Islamists since mid-September.
Last week, more than 50 people were killed in fighting between the rival sides, according to military and hospital sources.
In May, the authorities had accused the former Kadhafi-era general -- who spent years in exile before returning to join the 2011 revolution -- of trying to mount a coup.
But the internationally recognised interim government of Prime Minister Abdullah al-Thani "is now left with no choice but to make things up with Haftar", said Libyan analyst Fradj Najm.
Oil-rich and largely lawless Libya has two competing governments as well as a host of rival armed militias jostling for influence.
Parliament, elected in June, is recognised by the international community but contested by the militia controlling most of Tripoli and by the Islamists who dominate Benghazi.
Thani and the majority faction of that legislature decamped this summer to the far eastern city of Tobruk because of widespread insecurity, including in the capital, where a rival administration has been set up.
Clashes between rival militias have driven an estimated 287,000 people from their homes, including 100,000 who have fled the outskirts of Tripoli, according to the UN refugee agency.