Officers are appealing for anyone who may have witnessed the incident, which took place at around 18.35 hours on Friday, 18 May 2012 at the station.
Police Constable Mark Birdsall of British Transport Police said:
The train guard was opening the doors of the Leeds to Knaresborough service as it arrived at the station when he felt a blow to the left side of his face. His glasses were broken and lenses cracked.
Luckily the train guard avoided any serious injuries to his eyes but he has sustained pains to the side of his face and has been left with a pitched noise in his left ear.
This was an unprovoked attack on a member of staff simply doing his job; the incident has left him very shocked.
BTP will not tolerate assaults of any kind towards railway staff and we will do everything possible to track down the offenders and bring them to justice. The train was delayed and we are investigating claims that this assault may be linked to a disgruntled passenger due to this .I would like to appeal to anyone who may have witnessed the incident to contact police
Anyone with any information is asked to contact BTP on 0800 40 50 40 quoting incident 558 of 18/05/2012 Information can also be passed to the independent charity Crimestoppers, anonymously, on 0800 555 111.