Police have issued CCTV after two men reportedly attacked train staff at Cleethorpes station.
British Transport Police said two men became aggressive on December 21 at around 6.45pm before grabbing the train driver.
The train conductor also reported being grabbed by the men after trying to intervene.
Officers believe the men in the picture could have information that could help their investigation, but have not said whether they are suspects or witnesses.
Anyone who knows the men has been urged to contact BTP by texting 61016 or by calling 0800 40 50 40 and quoting reference 417 of December 21.
Contact Crimestoppers with information anonymously on 0800 555 111.