A man who challenged youths who were intimidating people in Edinburgh ended up in hospital after the group mounted a "vicious" attack on him.
The 37-year-old was attacked on Princes Street at the bus stop on the southside pavement, opposite Marks and Spencer, at about 22:35 on Monday.
Police said the six or seven teenage boys turned on the man, seriously injuring his face.
He was treated at Edinburgh Royal Infirmary.
Police are appealing for witnesses.
The attackers are about 15 or 16-years-old and were wearing dark puffer-style jackets. One of the youths had blond hair.
Det Con John Dunn, of Police Scotland, said: "The victim has attempted to come to the aid of a number of people who were being intimidated by the group of suspects. His intervention subsequently resulted in a vicous attack that left him requiring medical attention.
"We would urge anyone who was on Princes Street on Monday evening and witnessed this assault to contact police immediately.
"In particular, we would like to speak with the members of the public who were being hassled by the group and who may be able to provide us with more information that can help identify these youths."