The incident happened at approximately 7.20pm on March 2 at Inverkeithing on a service travelling between Edinburgh and Dundee.
The guard had asked the group to leave after they were being extremely anti-social.
You may also be interested in:
The group became aggressive, throwing the container which struck him, as well as a glass bottle which smashed off the train doors.
One of the persons involved is described as being a white man, approximately 20-years-old and of slim build. He was 6ft 2ins tall, clean shaven and wearing a brown flat cap, pink/white t-shirt, short jacket and navy jeans with white trainers.
Anyone who was on board or who recognises someone matching the above description is asked to contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 602 of 02/03/2019. Or call Crimestoppers anonymously on 0800 555 111.
Get in touch and tell us your story
Email: [email protected]