West Ham have vowed to hand supporters over to the police after a video online showed several Hammers fans singing a vile anti-Semitic chant which referred to Tottenham supporters as 'f****** Jews'.
The video appeared on social media on Saturday evening, in the wake of Manchester United's 2-1 victory over West Ham at Old Trafford.
In the footage fans could be heard chanting: 'We'll be running round Tottenham with our w****** hanging out... singing "I've got a foreskin, haven't you? F****** Jew!"'
The club have moved quickly to condemn the behaviour, which comes at the end of another damaging week in football's fight against racism.
West Ham say they are working to identify the offending fans and will hand the details of those involved to the police. Any supporter found to be involved will also be banned for life.
A West Ham United spokesperson said: 'We are disgusted by the contents of the video circulating on social media this evening.
'We are taking immediate action to try to identify the offenders, whose details we will be handing over to the police and will be banned for life from London Stadium and from travelling with the club.
'West Ham United is unequivocal in its stance – there is no place for this kind of behaviour at our Club. We do not want people like this associated with West Ham United. They are not welcome at our club, they are not welcome in civilised society.'
Earlier this week some Chelsea supporters were filmed singing a song referring to Liverpool's Muslim star Mohamed Salah as a 'bomber'.
One fan also claimed he was racially abused by fellow supporters during their Europa League clash with Slavia Prague, while Napoli defender Kalidou Koulibaly was the subject of racist abuse during his side's defeat by Arsenal.