CCTV images have been released after a group of men hurled "vile" racial abuse at a mother and her young son on a train to Bradford.

British Transport Police want help to identify the men involved in the incident, which happened on a Northern Rail service.

The mother was left "shocked and disgusted" by the incident, according to police.

She got on the 2.10pm service at Leeds and sat in a centre carriage with her four-year-old son, before getting off at Shipley.

It is reported that the men entered the same carriage at Leeds and immediately began using foul language.

They were also singing and chanting football songs throughout part of the journey, police said.

PC Craig Virco said: "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.”

Officers have now released a number of CCTV images of men they want to speak to as they are believed to have information about what happened.

PC Virco added: “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 members 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.”

The incident happened on Saturday, April 25.

Anyone with information should contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference PSUB/B9 of 06/05/2015. Information can also be passed anonymously to Crimestoppers on 0800 555 111.