London - FIFA president Sepp Blatter and UEFA have joined Chelsea in condemning an incident captured on video in the Paris metro, showing Chelsea fans pushing a black man off a train and chanting "we're racist".
The video was filmed before Chelsea's Champions League match against French champions Paris St Germain at the Parc des Princes on Tuesday evening.
The men can be heard chanting "we're racist, we're racist, and that's the way we like it".
Premier League leaders Chelsea, making their second visit to Paris for a Champions League match in less than a year, condemned the incident in a statement on Wednesday.
"Such behaviour is abhorrent and has no place in football or society," the club's statement said.
"We will support any criminal action against those involved, and should evidence point to involvement of Chelsea season-ticket holders or members the club will take the strongest possible action against them, including banning orders."
Blatter, the head of soccer's world governing body which has a zero tolerance policy towards racists, tweeted: "I also condemn the actions of a small group of Chelsea fans in Paris. There is no place for racism in football."
UEFA's statement read: "We are appalled by the incident which took place in the Paris Metro on Tuesday."
However, European soccer's ruling body, which also has a zero tolerance policy towards racism in stadiums, distanced itself from being able to take action against the fans or the London club.
"As it occurred away from the stadium, it is outside UEFA's remit to act," it said.
"It is a matter for the local authorities to investigate further and UEFA supports any action that is taken."
A Paris police prefecture spokesman said that no immediate complaint had been filed in relation to the video which was posted on the website of The Guardian newspaper.
"We will now assess the video of the (Richelieu-Drouot metro) incident and, if there is cause, launch an investigation in conjunction with our British colleagues," he added.
The spokesman said police, including about 10 British officers, had been deployed across Paris on Tuesday and prevented several fights from breaking out.
He said they had only just been apprised of the incident in the video, but added that, with the faces clearly visible, it should be easy to identify the men.
The amateur footage shows a black man trying to squeeze onto a busy train at the Richelieu-Drouot metro stop only to be pushed back repeatedly by a group of men.
After stopping him from boarding the train, they start their chants.
Paul Nolan, a British resident of Paris who filmed the video, told BBC Radio Four the Chelsea fans in the metro carriage had seemed "very aggressive" and it was an "ugly scene".