The United Nations human rights chief on Tuesday condemned the mass beheadings of Egyptian Christians in Libya and urged Libyans to fight Islamist extremists in their country. "The brutal murder of these men, and the ghastly attempt to justify and glorify it in a video, should be roundly condemned by everyone, in particular by the people of Libya who should resist the urgings of takfiri (Sunni extremist) groups," UN High Commissioner for Human rights Zeid Ra'ad Al Hussein said in a statement. Islamic State militants in Libya posted a video on Sunday showing the decapitation of 21 Coptic Christians who were in the country seeking work. "Murdering captives or hostages is prohibited under international law and Islamic law," he said, de**uncing what he called a "vile crime targeting people on the basis of their religion." UN human rights staff said Egyptian Coptic Christians have been abducted before in Libya.