The Ukrainian Parliament Commissioner for Human Rights, Dmytro Lubinets, commented Sunday on an incident in eastern Luhansk, saying Russian servicemen "are those who are fighting and committing treachery" and that "returning fire is not a war crime."
Russia has accused Ukraine of war crimes after video emerged on social media, which Moscow says shows Russian soldiers killed after surrendering to Ukrainian forces.
The precise details of what happened remain unclear.
"From some pieces of video about the incident with the Russian military in Luhansk region it may be concluded that using the staged surrender, the Russians committed a war crime — they opened fire on the military of the Armed Forces of Ukraine," Lubinets said in a Telegram post on Sunday, implying that the Russians from the video may have acted as if they would surrender but did not.
"In this case, persons among the Russian servicemen cannot be considered prisoners of war, but are those who are fighting and committing treachery," he said. "Returning fire is not a war crime. On the contrary, those who want to use the protection of international law to kill must be punished."
What the video appears to show: The edited video purports to show captured Russian soldiers in an act of surrender, with several men lying on the ground on their fronts with their hands over their heads. More soldiers are seen emerging one by one from a building and lying down next to them in the yard.
A voice apparently directing the surrender can be heard shouting: “Come on out, one by one. Which of you is the officer? Has everyone come out? Come out!"
After about 10 men are down on the ground, another soldier emerges from the same building and appears to open fire in the direction of the Ukrainian soldiers conducting the surrender.
A short burst of gunfire is heard before the video clip ends abruptly.
A second clip filmed later from a drone above the same location shows the bodies of what appear to be the same Russian soldiers in the yard, most just a few meters from where they had been lying in the first clip.
CNN has been unable to verify exactly what happened in the first video clip, and it is unclear exactly what happened in the period that elapsed between the first clip and the filming of the drone footage.
The UN investigates: Marta Hurtado, a spokesperson for the United Nations Human Rights Office, said, according to Reuters: "We are aware of the videos and we are looking into them. Allegations of summary executions of people hors de combat should be promptly, fully and effectively investigated, and any perpetrators held to account."
More context: A UN panel of experts said in September that their investigation has found evidence that war crimes have been committed during Russia's war in Ukraine, including cases of rape and torture of children.