The United Nations has raised concerns about the detention and mistreatment of a large group of Egyptian nationals in Libya at the hands of the Tripoli administration, saying it represents a possible violation of international law. Graphic footage has surfaced on social media that purportedly shows militias allied with Libya’s UN-recognised administration abusing Egyptian migrant workers captured in the western city of Tarhuna. Egypt has supported the eastern Libya-based Field Marshal Khalifa Haftar against the forces of the Tripoli government. The UN Mission in Libya said the mistreatment runs counter to the country’s “human rights law obligations on the prohibition of torture, inhumane and degrading treatment or punishment.” The Tripoli-based Interior Ministry issued a statement vowing to investigate the “criminal act” and arrest the perpetrators. In Egypt, where the videos have sparked outrage, Parliament Speaker Ali Abdel Aal said that the government would “determine the time and place of its response”. There are tens of thousands of Egyptians working in neighbouring Libya, although the number has declined since the 2011 uprising against Muammar Qaddafi. In the years of conflict that ensued, Libya has become divided between west and east, with the Tripoli-based Government of National Accord backed by militias in the west and the eastern administration backed by Field Marshal Haftar’s Libyan National Army. While the two sides have been locked into a near stalemate for the past year, the GNA militias have made a number of gains in recent weeks. The Turkish backed militias took Tarhuna, 65 kilometres southeast of Tripoli from the LNA. In the fighting, there have been accusations of human rights abuses. In a press conference on Tuesday, Faisal Jawal, a representative of the Libyan Red Crescent, said his teams were working to identify 106 dead bodies discovered in a Tarhuna hospital. Tripoli fighters allegedly took revenge on LNA allies by looting stores and destroying property across the town, according to the UN, as well as capturing a number of Egyptian migrant workers and subjecting them to “degrading treatment.” Egyptian President Abdel Fattah El Sisi announced a unilateral initiative to end the civil war earlier this month, but the offer of a ceasefire and dialogue has been rejected by Tripoli and Ankara.