Ukraine compared Russia on Wednesday to Islamic State, after a video emerged online showing apparent Russian soldiers filming themselves beheading a Ukrainian captive with a knife.
Reuters could not immediately verify the authenticity or provenance of the video shared on social media, which showed a man in uniform beheading a man who wears the yellow arm band used by Ukrainian soldiers.
There was no immediate comment on the video from Moscow, which has denied in the past that its troops carry out atrocities during the full-scale invasion Russia launched last year.
"There is something that no one in the world can ignore: how easily these beasts kill," Ukrainian President Volodymyr Zelenskiy said in a video message.
"There will be legal responsibility for everything. The defeat of terror is necessary."
Ukrainian Foreign Minister Dmitro Kuleba said on Twitter: "A horrific video of Russian troops decapitating a Ukrainian prisoner of war is circulating online.
"It’s absurd that Russia, which is worse than ISIS, is presiding over the UNSC," he said, referring to the U.N. Security Council where Russia took up the rotating presidency this month. "Russian terrorists must be kicked out of Ukraine and the UN and be held accountable for their crimes."
Militants from Islamic State in Iraq and Syria were notorious for releasing videos of beheadings of captives when they controlled swathes of those countries from 2014-2017.
Ukraine's domestic security agency said it had launched an investigation into a suspected war crime over the video.
"Yesterday, a video appeared on the Internet showing how the Russian occupiers are showing their beastly nature - cruelly torturing a Ukrainian prisoner and cutting off his head," the SBU agency wrote on Telegram.
(Reporting by Max Hunder; Editing by Tom Balmforth and Peter Graff)
