A fight between two groups erupted on a train from Lincoln to Grimsby, prompting British Transport Police to publish a CCTV appeal.
Two groups are reported to have had an argument on the 6.35pm train travelling from Lincoln on Saturday, February 1.
A fight broke out on arrival at Barnetby station at 7.20pm. Two people involved then left the station and the remainder of the group reboarded the train to Grimsby.
British Transport Police released a CCTV image on Tuesday, March 3 of two men officers would like to speak to, who they believe may have information that could help with the investigation.
Anyone who recognises them should contact BTP by texting 61016 or by calling 0800 40 50 40 quoting reference number 536 of 01/02/20.
Alternatively, it can be reported through the independent charity Crimestoppers on 0800 555 111.