British Transport Police have been called to Upney station in east London this afternoon following reports of a fight.
The station is currently closed while specialist crime scene officers collect evidence.
Officers from the BTP treated a man for a minor laceration at the scene, and he is now receiving further treatment from the London Ambulance Service.
An investigation is underway and at this time, police said, it is believed the men involved in the fight are known to each other.
Anyone with any information is asked to contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 273 of 20/01.