WARNING: GRAPHIC CONTENT

Shocking footage of a man violently stomping on the head of a male youth at a Melbourne train station is being investigated by police after it was uploaded to social media.

The first video, which was uploaded on Monday, shows a group of four young men walking up to the victim on the footpath outside what is believed to be Ringwood railway station.

A man in a white T-shirt then shoves the victim to the ground, before repeatedly kicking the teenager, who is believed to be 14, and then jumping into the air and using both legs to stomp violently on his head.