British Transport Police have made an appeal for further information following a homophobic incident on the London Underground.

A 19-year-old man was the victim of an attack on a Jubilee line train between West Ham and North Greenwich, where he was put in a headlock and forced to apologise for being gay.

The victim finally succumbed to the demand as he was struggling to breathe.

The offenders initially boarded the train at West Ham and began abusing the victim and his friends who were in fancy dress.

They used homophobic language against them before physically abusing the victim.

While the 19-year-old man was in a headlock, a second offender took his phone off him and threatened to stab him.

Related: Passengers jump from London train onto tracks over man ‘reading homophobic Bible verses’

Once he was out of the headlock after apologising, a fight broke out between the victim’s friends and the offenders.

One of the victim’s friends – a 25-year-old woman – was punched and pushed to the ground, and was left with bruising.

British Transport Police have released images of two men connected with the incident in a bid to collect more information.

The incident took place on 21 October around 11.10pm.

If you recognise either of the men in the images, please call BTP on 0800 40 50 40 or text 61016, quoting reference number 273 of 1/12.

“Hate crime will not be tolerated by British Transport Police. We believe that everyone has the right to travel safety,” they stated.

“We won’t tolerate behaviour where someone is targeted because they are perceived to be different, or made to feel uncomfortable on their journey.

Related: More than 1,000 schools to launch projects to stamp out homophobic bullying