THREE Chelsea fans were stopped from entering Slavia Praha's stadium for Friday's (AEST) Europa League game in Prague after an alleged racist chant about Liverpool's Mohamed Salah circulated on social media.

Chelsea, who will visit EPL leaders Liverpool on Monday (AEST), condemned in a statement any form of discriminatory behaviour, after a video showed supporters singing in an apparent derogatory reference to the Egyptian.

Merseyside Police said they were investigating publication of offensive Tweets made in relation to a Liverpool player.

Ex-Chelsea forward Salah, Player of the Year in England last season and winner of the African Footballer of the Year award for the second time in a row in January, is of Muslim faith.

The fans were prevented entry to Eden Stadium by Chelsea's security team.

"Chelsea FC finds all forms of discriminatory behaviour abhorrent and where there is clear evidence of Chelsea season ticketholders or members involved in such behaviour, we will take the strongest possible action against them," the Chelsea statement said.

"Such individuals are an embarrassment to the vast majority of Chelsea supporters who won't tolerate them in their club."

Liverpool said in a statement: "The video circulating online, showing vile discriminatory chants being aimed at one of our players, is dangerous and disturbing. This behaviour needs to be called out for what it is - unadulterated bigotry."

Chelsea won the first-leg clash in Prague 1-0.

- Reuters