Police have appealed for the public to help identify a group of football fans who allegedly hurled racist abuse at a mother and her four-year-old son on a train between Leeds and Bradford, in West Yorkshire.
The Barnsley FC fans were reportedly singing racist football chants on the train as they headed to watch their team play Bradford last month.
"A woman boarded the 2.10pm service at Leeds, sitting in a centre carriage with her four-year-old son," said PC Craig Virco, who is leading the investigation. "Soon after, a group of men entered the same carriage and immediately began using foul language, singing, and chanting football songs.
"The group then began repeatedly using racist language, some of which was directed at the young boy. They ignored the mother's requests to stop. When she stood up to leave the train at Shipley, she again challenged the group's behaviour, only to become the target for more abuse."
He added: "As is understandable, the mother left the train hugely upset, shocked and disgusted at the vile abuse directed and her very young son, and promptly contacted police.
"Now we are calling on member of the public to help. Do you recognise any of the men pictured? Were you on the train in question? If so, we want to hear from you."
British Transport Police have issued images of several men they would like to speak to in connection with the incident, and have appealed for other witnesses who may have been on the train to come forward.
The incident allegedly took place on Saturday, 25 April shortly after 2pm on a Northern Rail service between Leeds and Bradford Forster Square.
Police have asked anyone with information to contact them on 0800 40 50 40, or text 61016, quoting reference PSUB/B9 of 06/05/2015.
Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.