British Transport Police detectives appealing for information after a train carriage was damaged by a group of men believed to be travelling to a football match on Friday 24 September.
Six men have been arrested in connection with the incident and the BTP has now released images of two men they believe may have further information.
"We believe the group of men were travelling to watch Crystal Palace play Charlton at The Valley around 7pm," said Detective Constable Jason Schweiger.
"They had boarded a crowded commuter train at London Bridge and began pulling down light gratings, ripping off and throwing seat covers, smashing light bulbs and banging on and attempting to break windows.
"They were also heard to be chanting.
"This was obviously an intimidating experience for other passengers and we have conducted an in-depth investigation into the incident to try to identify the people responsible.
"This has included working through forensic opportunities, viewing CCTV footage and speaking with witnesses. Images have also been circulated to other police forces and on police intelligence systems but unfortunately to no avail.
"From viewing CCTV on board the train we have now isolated images of four men we would like to speak to. This was a packed train and I am certain that there are people out there with information that could help our investigation."
If you recognise the men pictured, or have information about the incident, please call British Transport Police on 0800 40 50 40 quoting reference B7/LS of 12/12/12. Alternatively you can contact Crimestoppers anonymously on 0800 555 111.