Human Rights Watch on Wednesday accused putschist Gen. Khalifa Haftar's forces of laying Russian landmines in the residential southern suburbs of the Libyan capital.
"An armed group and affiliates fighting for control of the Libyan capital Tripoli appear to have used antipersonnel landmines and booby traps there in late May 2020," the New York-based rights group said.
"Fighters affiliated with the Libyan Arab Armed Forces (LAAF) commanded by Khalifa Haftar, including foreign forces, appear to have laid mines as they withdrew from southern districts of the city."
The report came days after the United Nations Support Mission in Libya (UNSMIL) said it was "extremely concerned about reports that residents of the Ain Zara and Salahuddin areas of Tripoli have been killed or wounded by Improvised Explosive Devices placed in/near their homes."
HRW said the antipersonnel mines discovered in Tripoli in May were "of Soviet and Russian origin."
Warlord Haftar's forces have been battling since April last year to seize Tripoli from the U.N.-recognized Government of National Accord (GNA), in fighting that has left hundreds dead and forced 200,000 to flee their homes.
Immediately after the last cease-fire proposal, Haftar declared himself the sole ruler of Libya, dropping the U.N.-brokered Skhirat agreement signed in 2015 between Libyan warring sides, – a move that was condemned by international actors and regional allies.
Haftar, however, was unable to overthrow the Tobruk-based House of Representatives and its speaker Aguila Saleh, as he enjoys major tribal support in east Libya.
Haftar's fighters in May pulled back from areas of southern Tripoli that they had held for months, following key defeats on other fronts.
On Wednesday, residents of Mashrou al-Hadba, a suburb heavily damaged in the fighting, were able to return home after an absence of more than a year, accompanied by security experts to keep them out of mined areas, Health Ministry spokesman Amine el-Hashemi wrote on Twitter.
Haftar's rapid advance on Tripoli last year stalled to a bloody stalemate on the edges of the capital.
In recent weeks, GNA forces armed with Turkish drones and air defense systems have taken back a string of coastal towns and a key airbase.
Haftar is supported by neighboring Egypt and the United Arab Emirates as well as Russia.