A train has derailed near Rushall Station in Fitzroy North.

The six-carriage city-bound train travelling on the South Morang line was carrying 120 passengers when one of the wheels of a single carriage came off the tracks about 5pm on Saturday evening just 100 metres from Rushall station.

Passengers were evacuated from the train with the help of police who were already on board.

A man was taken to St Vincent's Hospital suffering minor back injuries following the incident.

No other passengers aboard the train were reported to suffer injuries.

The derailment on the X'trapolis train led to rail services being suspended between Clifton Hill and Bell stations, with replacement bus services shuttling passengers.

A Metro Trains spokeswoman Sammi Black said the safety regulator were still on the scene and had yet to give clearance for Metro operations team to recover the derailed train. 

The cause of the derailment is not yet to be determined. "It is too early to speculate, we're still investigating," she said.

With the damaged train still on the railway track, Ms Black said it was unclear whether rail services would resume between Clifton Hill and Bell stations tomorrow, or whether bus would continue to operate.

Public Transport Victoria has provided a list of replacement services.