International human rights groups are urging both Azerbaijan and Armenia to urgently conduct investigations into war crimes allegedly committed by both sides during weeks of recent fighting over the breakaway Nagorno-Karabakh region.

Amnesty International has analyzed 22 videos depicting “extrajudicial executions, the mistreatment of prisoners of war and other captives, and desecration of the dead bodies of enemy soldiers,” the London-based human rights watchdog said in a statement on December 10.

Two of the clips show “extrajudicial executions by decapitation” by members of Azerbaijan’s military while another video shows the cutting of an Azerbaijani border guard’s throat that led to his death, it said.

“The depravity and lack of humanity captured in these videos shows the deliberate intention to cause ultimate harm and humiliation to victims, in clear violation of international humanitarian law,” according to Denis Krivosheyev, the rights group’s research director for Eastern Europe and Central Asia.

“Both Azerbaijani and Armenian authorities must immediately conduct independent, impartial investigations and identify all those responsible,” Krivosheyev said.

Louis Charbonneau, the United Nations director at New-York based Human Rights Watch, said the abuses described by Amnesty were “war crimes” that should be investigated.

“Azerbaijan and Armenia authorities [should] investigate, identify [people] responsible & hold them accountable,” Charbonneau said on Twitter.

Amnesty International “authenticated the footage as genuine, and technical tests conducted on the videos indicate that the files have not been manipulated,” the statement said, adding that a forensic pathologist verified the details of the injuries.

International humanitarian law prohibits acts of violence against prisoners of war and any other detained person, the mutilation of dead bodies, and the filming of confessions or denunciations for propaganda purposes.

Amnesty International’s call comes one month after a Moscow-brokered cease-fire deal brought an end to six weeks of fighting in and around Nagorno-Karabakh — the worst clashes over the disputed region in three decades.

The latest fighting left more than 5,000 people dead, including many civilians, and resulted in Azerbaijani forces retaking much of Nagorno-Karabakh and surrounding districts.

Both sides have accused each other of violating international law during the war.

The region, populated mainly by ethnic Armenians, declared independence from Azerbaijan amid a 1988-94 war that claimed an estimated 30,000 lives and displaced hundreds of thousands of people.

Internationally mediated negotiations have failed to result in a resolution.