NEW YORK — The UN High Commissioner for Human Rights has warned of possible war crimes in the ongoing fighting between Armenia and Azerbaijan in the Nagorno-Karabakh conflict zone.

“Since the conflict reignited in September with the terrible consequences we are now seeing, there have been repeated calls, including by myself, for the parties to take all feasible steps to avoid, or at the very least minimize, the loss of civilian life and damage to civilian infrastructure, including schools and hospitals — as well as to distinguish civilians from combatants, and civilian objects from military objectives,” she said.

“International humanitarian law cannot be clearer. Attacks carried out in violation of the principle of distinction or the principle of proportionality may amount to war crimes, and the parties to the conflict are obliged to effectively, promptly, thoroughly, and impartially investigate such violations and to prosecute those alleged to have committed them.”

The Nagorno-Karabakh conflict has persisted for more than three decades. Although located within Azerbaijan, the region has been under the control of ethnic Armenian forces since the parties fought a war as the Soviet Union was dissolving.

The UN rights chief said despite an agreement reached on Friday by Armenia and Azerbaijan, which called for refraining from deliberately targeting civilian populations, artillery strikes against populated areas were reported over the weekend.

The Azerbaijani Government reported that since fighting resumed in September, at least 91 civilians have been killed in areas under its control, while the Armenian Government said 45 people have been killed in the Nagorno-Karabakh conflict zone, and two within its borders. The UN Human Rights Office (OHCHR), which Bachelet heads, has not been able to independently verify these figures.

The UN rights chief also noted that the biggest loss of life occurred on Oct. 28, when some 21 people were reportedly killed, and 70 others injured, in a rocket attack on the Azerbaijani town of Barda, roughly 30 km from the area of active hostilities.

The rockets, allegedly fired by Armenian forces from Nagorno-Karabakh, reportedly carried cluster munitions.

“Amid deeply troubling reports that cluster munitions have been used by both parties, I call once again on Armenia and Azerbaijan to stop using them, and to join the more than 100 States that have ratified the Convention on Cluster Munitions which comprehensively bans their use,” the High Commissioner said.

The conflict has also caused widespread displacement, and Bachelet urged the parties to “depoliticize the issue of providing human rights and humanitarian access” to affected areas, including by UN teams.

The High Commissioner also expressed serious concern over videos that appear to show war crimes being committed.

Although she said fake images have been circulated on social media, in-depth investigations by media organizations have uncovered “compelling and deeply disturbing information” surrounding videos that appeared to show Azerbaijani troops summarily executing two captured Armenians in military uniforms.

The willful killing of protected persons represents a grave breach of the Geneva Conventions, the international treaty which established the standards for humanitarian treatment during wartime.

Ms. Bachelet explained that while such an incident would constitute a war crime, only a competent court can determine and rule on this.

With the fighting taking place amid rising cases of COVID-19, the UN rights chief underscored the direct threat to public health, adding that “the fighting is also strikingly in opposition to the UN Secretary-General’s call for a global ceasefire amid the pandemic.”

Bachelet reiterated her call for all parties to protect civilians and civilian infrastructure, abiding by the principles of distinction, proportionality, and precaution, and avoiding the use of explosive weapons in populated areas.

“As the loss of life continues and the suffering of civilians deepens, I appeal again for an immediate halt in the fighting and urge all parties to abide by a humanitarian ceasefire and engage in negotiations to find a peaceful and durable solution to this conflict that has wrought so much destruction in the region,” she said.