A fire has damaged part of the Westall Railway Station in Rayhur Street, Clayton South.
Police were called to the station about 11.30 pm last night after an initial report of a minor assault.
There were reports of youths seen running away from the railway station.
A fire was found burning at the station which police believe started in a waiting room area.
The fire damaged the ticket office area as well as the waiting room and a ticket machine.
Police are treating the fire as suspicious and a guard has been placed on the scene overnight.
Further investigations into the exact cause of the fire will be carried out later this morning.