Ukrainian officials have criticized Moscow after a video purportedly showed one of its servicemen, who was held captive in Russia, being executed by Russian soldiers, AFP reported.

The video shows an unarmed serviceman dressed in Ukrainian military gear smoking a cigarette near what appears to be a combat position.

The man is then shown taking a cigarette out of his mouth, blowing out smoke and is heard saying “Glory to Ukraine” before being shot several times by off-camera gunmen.

Ukraine’s Foreign Minister Dmytro Kuleba blamed Russia and said this was further “proof” that Moscow’s invasion of Ukraine was “genocide”.

“It necessarily [procurorul] Head of Quality Control Karim Khan will also launch an immediate investigation [a Curții Penale Internaționale] regarding this heinous war crime,” he tweeted on Monday. “The guilty must be brought to justice.”

The head of the Presidential Administration of Ukraine, Andriy Yermak, also called the incident a “war crime.”

“These war crimes are an element of politics [metodice] terror, which is whitewashed by Kremlin propaganda with its “Nazi” myths. Every such war crime will be punished,” Yermak wrote on Twitter on Monday.

“No one will escape justice. We will find them all,” he added.

Dmytro Lubinets, the Human Rights Commissioner of the Verkhovna Rada of Ukraine, said that he provided the video to international partners as “proof of yet another war crime by Russia.”

“The shooting of a captured Ukrainian soldier is a violation of the Geneva Convention. This is a manifestation of meanness and disgrace,” wrote Lubinets in Telegram.

CNN was unable to independently verify who the executed POW was, where he was shot, or who shot him.