London - Chelsea on Thursday urged their fans to keep their support "positive" in Sunday's League Cup final against London rivals Tottenham Hotspur, amid fears over anti-Semitic chanting.
Tottenham have long-established links with the Jewish community and Chelsea admitted that previous games between the teams had featured "a deeply unpleasant and unwanted level of anti-Semitic abuse".
Chelsea's fans have come under scrutiny after footage emerged showing a group of supporters preventing a black man from boarding a Paris metro train last week and chanting racist songs.
"Sunday's Capital One Cup final against Tottenham Hotspur at Wembley promises to be a passionate and exciting match with both sets of supporters contributing to an excellent occasion," Chelsea said in a statement on their website.
"After consultation between the Metropolitan Police and both clubs, we would like to remind supporters of their responsibilities on the day.
"For a small minority, this game has historically brought a deeply unpleasant and unwanted level of anti-Semitic abuse, which has no place in football or anywhere in society. As such, we urge everyone to keep their support positive."
They added: "If we receive evidence that supporters have engaged in anti-Semitic or any other form of discriminatory chanting or behaviour, we will take the strongest possible action, including supporting criminal prosecution."
Chelsea have banned five supporters from Stamford Bridge in the light of the Paris incident, which occurred before their 1-1 draw at Paris Saint-Germain in the Champions League.
"Recent events in Paris have seen Chelsea fans united in their contempt for a mindless few," the statement continued.
"Chelsea is proud of the diversity within our club and our vision embraces equality regardless of race, gender, sexuality, disability or religion. We all share the common cause of supporting our team."