The United Nations' Libya mission warned Friday that armed groups in the sensitive region of Sirte were preventing civilians from accessing vital services.
"UNSMIL is following closely reports of restrictions on freedom of movement of civilians as part of security operations in Qasr Bouhadi", about 20 kilometres (12 miles) from Sirte city.
Libyan media have reported arrest campaigns targeting the Gadadfa, the tribe of former dictator Moamer Kadhafi, Qasr Bouhadi's most famous son, whose fall and killing in a 2011 revolt plunged the country into more than a decade of turmoil.
UNSMIL said it had "received worrying reports that these restrictions are preventing access by civilians to hospitals, schools, shops, and other essential facilities."
It said civilian freedom of movement should be restored and called "for the release of all arbitrarily detained individuals".
Libya has seen two years of relative peace since the last major combat between eastern and western camps ended with a ceasefire in mid-2020 along a line from Sirte to the city of Jufra.
But this year a new struggle has emerged between a Tripoli-based interim government and another administration appointed by the eastern-based parliament which has so far failed to take up office in the western capital.
The parliament-backed government of former interior minister Fathi Bashagha is backed by military strongman Khalifa Haftar who controls much of the country's east up to Sirte.
On Thursday, interim premier Abdulhamid Dbeibah said Qasr Bouhadi residents were facing "unacceptable injustice".
