A group of men, believed to be Chelsea fans, are being hunted by police after being heard shouting racist chants at St Pancras station.
The men were returning from Paris by train on Wednesday, the day after the club played Paris St Germain in the French capital.
The incident happened at the central London station at around 8pm, and was reported by a member of the public who was "disgusted" by their behaviour, the British Transport Police (BTP) said.
It comes after police released images of three men - believed to be Chelsea fans - who they want to speak to in connection with a separate incident on the Paris Metro on Tuesday.
A group of fans were captured on video stopping a black man boarding a train and chanting: "We're racist, we're racist, and that's the way we like it."
Speaking about the incident at St Pancras station, Superintendent Gill Murray of the BTP said: "The men shouted as they walked through the station having alighted from the train a short time earlier.
"If you travelled on the train from Paris or were at the station and have information which can assist our investigation I would urge you to get in touch as a matter of urgency."
The club has suspended five people from Stamford Bridge, the club's stadium, while it investigates the incident on the Paris Metro.
