London - Chelsea have vowed to take the "strongest possible action" against any supporters found to have used anti-Semitic language in a chant about the club's new striker Alvaro Morata.
The song, aired during Chelsea's 2-1 win at Leicester City on Saturday, describes supporters of rivals Tottenham Hotspur, who have traditional links to the Jewish community, as "Yids".
Chelsea and Morata denounced the chant after the game, the club pledging to support police in helping to identify offenders, and a club spokesman reiterated the message on Monday.
"Chelsea Football Club finds all forms of discrimination abhorrent and the language that was used in that song the other night we find totally unacceptable," said head of communications Steve Atkins.
"People that use this kind of language against others always try to argue a grey area. There is no grey area. That language used was anti-Semitic. We have a zero-tolerance policy towards it.
"If there is evidence that season ticket holders or members took part in that, and take part in it in the future, then we will take the strongest possible action against them, which includes bans."
He added: "We must be clear on this because it has to stop."
Chelsea, Leicester and England's Football Association have vowed to work together to aid a police investigation into the chant.
Speaking at a press conference ahead of Chelsea's Champions League opener against Azerbaijani side Qarabag on Tuesday, manager Antonio Conte backed the club's stance.
"We are totally agreed with the club," said the Italian.
"You know very well that I love our fans, because they push us a lot during the game. But I think we must pay great attention in the future."