At least nine soldiers were killed in an attack on a training camp belonging to the eastern Libyan armed forces of Khalifa Haftar in the city of Sebha.
Libyan officials say militants have killed at least nine soldiers in an attack on a training camp for the self-styled Libyan National Army (LNA) in the country's southwestern desert.
The officials said militants clashed on Saturday with guards near an air base seized earlier this year by the LNA in the city of Sebha.
The officials spoke on condition of anonymity because they were not authorised to talk to media.
Daesh has claimed responsibility for the attack.
Sebha is 650 kilometres (400 miles) south of the capital, Tripoli, where Field Marshal Khalifa Haftar's LNA forces are currently fighting to take control of the city from militias affiliated with a weak UN-supported government.
The UN humanitarian agency said on Friday that the month-long assault on Tripoli has displaced nearly 55,000 people.
The LNA faced strong opposition from the Tebu ethnic group during its campaign in the south at the start of the year.
Daesh militants are also active in southern Libya where it has staged several hit-and-run attacks in recent months. It retreated to the south after losing its stronghold in the central city of Sirte in December 2016.