Amnesty International on Tuesday accused Muammar Gaddafi's regime of crimes against humanity in Libya but also accused the NTC fighters who overthrew him of having committed war crimes.
Amnesty's 122-page report consisted mainly of damning examples of violations by Gaddafi's regime.
But it also noted that the National Transition Council (NTC) appeared unwilling to hold its fighters accountable for human rights violations.
"The NTC is facing a difficult task of reigning in opposition fighters and vigilante groups responsible for serious human rights abuses, including possible war crimes; but has shown unwillingness to hold them accountable," Amnesty said.
"Opposition officials with whom Amnesty International raised these concerns condemned such abuses, though they have often downplayed their extent and gravity," it added.
"Opposition fighters and supporters have abducted, arbitrarily detained, tortured and killed former members of the security forces, suspected Gaddafi loyalists, captured soldiers and foreign nationals wrongly suspected of being mercenaries fighting on behalf of Gaddafi forces," Amnesty said.
Amnesty detailed one incident at the beginning of the uprising in which a number of Gaddafi soldiers were "beaten to death, at least three were hanged, and others were shot dead after they had been captured or had surrendered."
The report also detailed cases of what appeared to be summary executions, arbitrary detention and torture of individuals associated with the Gaddafi regime.
Amnesty acknowleged that the war crimes allegedly committed by the now governing opposition were of a "smaller scale" than that of Gaddafi's regime, which it says may be responsible for crimes against humanity.
The Amnesty report, entitled "The Battle for Libya -- Killings, Disappearances and Tortures", is the most recent document to give detailed accounts of violations in Libya.
Amnesty urged that all the alleged crimes be investigated, and the perpetrators brought to justice.
"Allowing them to escape justice will send a message that serious human rights violations will continue to be tolerated," it concluded.
