This is the moment a man stumbles forwards and whacks his head against a moving train, causing a serious head injury.
The incident was filmed at Vladykino station on the Serpukhovsko–Timiryazevskaya line of the Moscow Metro in the Russian capital on Sunday, 26th December, and the footage has been widely shared on the social network Telegram.
In the video, the train is seen moving past the platform as the victim appears and apparently loses his balance.
The man stumbles forwards head-first and falls against the moving tube, hitting his head against the side of the train and crashing to the floor unconscious.
His beanie hat is seen flying off and landing on the platform a few feet away from his splayed body.
Another man is seen walking onto the platform, and he is seen turning back where he came from as soon as he sees the injured man lying on the platform as the clip ends.
According to local reports, the man hit his head against the moving train after just arriving at the metro station.
He reportedly suffered a serious head injury in the incident and was taken to a Moscow hospital for emergency treatment.
It is unclear what caused the man to stumble forwards and injure himself and there have been no further updates on his condition as the police investigation continues.
Local media did not report his identity.
According to local media outlet REN TV, the police had to detain another passenger at Borovitskaya metro station in Moscow that day for relieving himself in a public area instead of using a toilet.