A woman has been left traumatised after her head was smashed into the side of train carriage during an apparent racial attack in Melbourne's north.

The 26-year-old victim was on an Upfield line train outbound on Thursday night when she was approached by another woman, who began hurling abusive and racist remarks.

The woman grabbed the victim by the neck and hair, and forced her head into the wall of the carriage several times.

She then pushed the victim off the train as it rolled into Batman Station in Coburg North.

Senior Constable Michael Potter said the incident occurred as the train approached the station about 6.55pm on Thursday night.