Ukraine on Wednesday vowed to look into the grueling footage that has been going viral online showing a Ukrainian soldier being beheaded. Kyiv authorities expressed outrage, and the Kremlin has called the video "terrible" but said it has to be validated.

In the Ukrainian soldier beheading clip, a man wearing the classic Ukrainian fighters' green outfit and yellow wristband was seen screaming as a man wearing camouflage beheads him with a knife, AP News reported.

The footage shows three males; two of them converse in Russian, while the third is seen with the victim's flak jacket.

White and yellow armbands, used by opposing sides as identification during the continuing battle, can be seen in the clip, making it difficult to pinpoint when it was shot.

The Ukranian soldier beheading footage was likely shot in late spring or summer of the prior year, given the lush greenery in the background. Several internet users have theorized that it was filmed around July, although this is unverifiable.

On Tuesday night, a pro-Kremlin blogger with over 300,000 followers published the Ukranian soldier beheading video on Telegram, and it quickly went viral, according to the BBC.

The Ukrainian Ministry of Internal Affairs (SBU) has reportedly opened a probe into allegations of a war crime. The agency said in a Telegram post that a Russia-Ukraine war video showing Russian invaders cruelly torturing and executing a Ukrainian prisoner had gone viral.

EU Condemns Ukrainian Soldier Beheading Video

The European Union has vowed to bring to justice anyone guilty of war crimes. EU spokeswoman Nabila Massrali said that the EU does not have enough evidence to verify the video's authenticity but that it serves as a stark reminder of Russia's cruel behavior in the Russia-Ukraine war.

Another video, depicting two beheaded Ukrainian troops lying next to a wrecked military vehicle, has been circulating on pro-Russian social media networks. The unverified footage showed dead troops with their hands chopped off, per Al Jazeera.