The video, which began circulating on March 27, shows three men in fatigues, hands bound behind their backs, thrown to the ground by armed men who then shoot them in the legs.

While the authenticity of the footage could not be independently confirmed, AFP was able to geolocalise it to the village of Mala Rogan outside the northeastern city of Kharkiv, which Ukrainian forces had just recaptured after an offensive.

AFP journalists were able to visit Mala Rogan on March 28 and saw the bodies of two Russian soldiers lying on one of the streets of the village, which was to a large extent destroyed by fighting.

Two other bodies were partially visible under pieces of concrete in a well.

"If confirmed, the beating and shooting of captured combatants in their legs would constitute a war crime," Human Rights Watch said in a statement late on Thursday.

"Ukraine needs to demonstrate that it is able and willing to prevent and punish serious violations of international humanitarian law," it added.

Ukrainian presidential advisor Oleksiy Arestovich acknowledged on Telegram that abuse of prisoners constitutes a war crime and should be punished.

"We treat prisoners in accordance with the Geneva Convention despite your personal emotional motivations," he said to Ukrainian soldiers.

The head of Russia's main criminal investigative force has also ordered a probe into the incident.

Russian soldiers have also been accused of committing abuses since launching their invasion on February 24.