The United Nations said on Friday it was "deeply concerned" over alleged summary executions of prisoners of war by Russian and Ukrainian forces on the battlefield.
The allegations came shortly after Kiev accused Russian forces of killing captured Ukrainian soldiers.
Matilda Bogner, head of the UN Human Rights Observation Mission in Ukraine, said her organization recently registered killings from both sides.
At a news conference in Kiev on Friday, Bogner said she was "deeply concerned about the summary execution by the Ukrainian army of up to 25 Russian prisoners of war and incapacitated people."
"This was often committed on the battlefield immediately after capture," she said. "We are aware that Ukrainian authorities are investigating five cases involving 22 victims, but we are not aware that the perpetrators have been prosecuted," she added.
Bogner also expressed "deep" concern over the alleged execution by Russian forces of 15 of her Ukrainian prisoners of war.
She said the Wagner mercenary group, which it claims is leading the Russian offensive against Bakhmut, is responsible for 11 of those killings in what it claims is the longest and bloodiest battle of the war. .
Ever since Russian President Vladimir Putin invaded a year before him, Moscow and Kiev have accused each other of mistreating prisoners of war.
Kiev's foreign ministry told a UN report that it was "unacceptable" to hold "victims of the aggression" accountable. – “They broke us” –
A United Nations report released on Friday alleged that Ukrainian military personnel threatened prisoners of war with death threats, mock executions or threats of sexual violence. Some of the blows were "pure retaliation," he said.
"In some cases, officials beat prisoners by saying:
"This is for Bucha," a mission reported by a detainee, referring to a town near Kiev where Russian forces have been accused of widespread atrocities.
"Before being interrogated, I was shown a bloody ax handle as a warning," the report quoted a Russian prisoner of war as saying.
"The interrogation lasted about an hour and they used electricity six times when they thought I was lying," detainees said, according to the report. Ukrainian prisoners of war cited in the report said they were subjected to torture, sexual violence, lack of food and water, and were denied medical care.
They said they were tortured and ill-treated to extract information or as punishment.
Ukrainian prisoners reported being beaten with shovels, stabbed, electrocuted and strangled.
"Some of them lost teeth or fingers and had broken ribs, fingers or noses," the report said.
"They not only beat us, they beat us. They used fists, legs, batons and tasers. Some prisoners had broken arms and legs," said one man.
Ukrainian parliamentary human rights commissioner Dmitro Rubinets said on Friday he was "surprised" by the allegations against the Ukrainian army, saying he had not been informed beforehand.
He wrote on Telegram that he wanted to know the "facts and incontrovertible arguments on which the conclusions were based" of the UN report.
In a separate statement on Friday, Kiev's foreign ministry said it thanked the UN observers for their work, but Ukraine warned that "the UN mission could be interpreted as putting victims and aggressors on an equal footing." We hope to avoid any measures," he said.