Police are appealing for information after a "vicious and nasty assault" in which men broke a teenager's jaw after shouting homophobic abuse at him.
Last Saturday at 9:30pm the 16-year-old boy was walking through Nelson town centre in Lancashire, when three men began shouting abuse.
Police say an argument broke out before the men assaulted the teen, who was with his sister. He was then punched and kicked in the face.
In a statement, Lancashire police said they were appealing for information: "The offenders were disturbed when a man who was passing intervened and they all left the scene.
"The victim was left needing surgery for a broken jaw and police are appealing for anyone with any information to come forward."
Detective Constable Julie Leigh, investigating, described the assault as "vicious and nasty" and appealed for witnesses to come forward.
“In particular, I would like to speak to the man who intervened and was able to stop the assault and would urge him, if he sees or hears this appeal to contact us," she said.
“I would also appeal to anyone else that may have been in the area at the time who may have witnessed anything or to anyone that recognises the descriptions of the offenders to contact us.”
The men are described as Asian and aged between 16 and 19.
Police said: "One of them in particular was described as being of medium build, around five feet eight and five feet 10 inches tall and clean shaven with short, dark cropped, hair. He was wearing dark clothing."
Anyone with any information should contact police by calling 101 or alternatively contact the independent charity Crimestoppers anonymously on 0800 555 111 or online at Crimestoppers-uk.org.