Police are hunting a group of 20 Chelsea fans who are alleged to have sexually assaulted women on a train and chanted racial abuse in front of children.
The men were travelling on the 6.22pm service from London Paddington to Worcester on December 22 when they went on the rampage.
British Transport Police is appealing for witnesses to contact them, as well as a number of women they say were assaulted but who have not yet come forward.
The force said in a statement: "On December 22 a group of around 20 football fans boarded the 6.22pm Great Western Service from London Paddington and began to chant racially abusive comments in front of families and children.
"They were also seen to sexually assault a number of women on board the train. It is believed they were Chelsea fans."
The group left the train at Worcester.
There have been a string of allegations made against Chelsea fans in recent months, including claims of anti-Semitic chanting during a Europa League game in Hungary; alleged racist abuse of Manchester City forward Raheem Sterling and discriminatory chants during a Boxing Day match against Watford.
Chelsea Manager Maurizio Sarri and his Spurs counterpart Mauricio Pochettino have warned fans to behave during Tuesday's Carabao Cup semi-final first leg at Wembley.
Anyone with information can contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 216 of 04/01/19.