If confirmed, the actions would breach the rules of war, and could amount to a war crime.

In a briefing on Tuesday in Geneva, OHCHR Spokesperson Ravina Shamdasani pointed to audio that emerged on Sunday on several Telegram channels, which urged combatants not to bother taking POWs, or to summarily execute those captured.

Take no prisoners

She said one recording was “alleged to be of a member of the Ukrainian armed forces ordering the killing of a prisoner of war from the so-called Wagner Group”, the mercenary force run by Yevgeny Prigozhin, which is fighting alongside Russian troops, notably in the months-long battle for Bakmut.

“A subsequent audio statement was issued, apparently from the head of the Wagner Group, indicating that they would no longer take prisoners of war on the battlefield”, she said.

The OHCHR Spokesperson said that while the authenticity of the recordings on the encrypted app had not yet been confirmed, “such statements could provoke or encourage summary executions of prisoners of war or those hors de combat” – meaning troops who have been injured in battle.

War crimes, if verified

She said if it was verified, the order to summarily execute injured combatants, including POWs, “followed by their killing or an attempt to do so, amounts to a war crime, as does the declaration that no quarter will be given.”

“We call on Russian and Ukrainian authorities to comply with their obligations under international law to investigate the statements in these recordings and to identify and prosecute those responsible”, added Ms. Shamdasani.

‘Clear and unambiguous orders’

She also called on military commanders on the ground in Ukraine, and their superiors, to issue “clear and unambiguous orders to protect and treat humanely POWs and persons hors de combat, and to ensure that these orders are strictly complied with.”