He said: “The man, quite rightly, took offence to these vile songs and challenged the group over their language. However, they refused to stop and continued with their chanting.
“This sort of casual racism has gone unchallenged for too long.
“We know the vast majority of football fans are decent people, but for those who continue to make life unpleasant for the travelling public, our message is clear: we will not tolerate your yobbish behaviour.”
In a separate incident, a group of West Ham supporters were investigated in February after being filmed taking part in antisemitic singing on a Tube train.
The club has said that any fans found guilty of antisemitic abuse could face a life ban from its ground.
Anyone with information on the latest incident is asked to contact the British Transport Police on 0800 40 50 40 or by texting 61016, quoting the reference MSUB/B4 of 12/10/2015.
Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.
