At least 19 Libyan army soldiers have been killed and dozens of others injured after the UN-recognised government launched a new offensive in a bid to retake the eastern city of Benghazi, officials say.
The North African nation is split is between an elected parliament and weak government, which was forced to relocate from Tripoli to the far eastern cities of Tobruk and Bayda, and a rival government and parliament in Tripoli set up by a group of armed groups.
Majlis al-Shura, an umbrella of powerful armed groups that rule over Tripoli, currently controls Benghazi.
The latest offensive targeted the district of al-Laithi, a stronghold for armed groups, as army jets bombed multiple positions overnight and early on Thursday morning, a military official has said.
Backed by helicopters, army special forces took back several government buildings in Benghazi, Libya's second-largest city, the official said.
The bodies of six soldiers were brought to the Benghazi Medical Centre, according to Khalifa Gwaider, a hospital spokesperson.
A second army official, speaking on condition of anonymity because he was not authorised to speak to the media, said 13 bodies were brought to other area hospitals.
At least 30 other troops were wounded in the clashes, a military spokesperson said.
Nearly four years after the toppling of longtime leader Muammar Gaddafi, Libya is consumed by fighting between rival governments and armed groups.
The army has gained some territory but clashes continue almost daily despite repeated claims by Khalifa Haftar, the top commander, that his forces have been dominating.
In another development, a suicide car bomber attacked a checkpoint 60km east of the western city of Misrata, killing one soldier and injuring three, a witness said.
In a short statement posted on social-networking sites, a group affilitated with the Islamic State of Iraq and Levant (ISIL) group in Libya claimed responsibility for the attack.
Bombing in Sirte
On Wednesday, ISIL also claimed responsibility for a suicide bombing near the central city of Sirte in which a bomber detonated his device at a checkpoint near the town of Hawara, killing one soldier.
Taking advantage of the security vacuum, ISIL fighters seized Sirte, Gaddafi's home town east of Tripoli, earlier this year.
ISIL fighters clashed with forces sent from Misrata allied to the Tripoli-based self-declared government, officials and residents in Sirte said.
One member of the Misrata-based Brigade 166 was killed and seven were wounded in Wednesday's battles, Jamal Zubia, a spokesperson for the Tripoli-based government, said in a message on social media.
ISIL said in a Twitter message its fighters had seized a camp of Misrata forces in southeast Sirte.
The group published pictures purportedly showing its fighters at the camp, seizing several vehicles. A resident said the camp seemed to be in the hands of ISIL.
ISIL fighters have in recent months claimed responsibility for several attacks including the storming of a Tripoli hotel and the murder of dozens of Egyptian and Ethiopian Christians.