A gang in the Midlothian village of Mayfield has attacked a 15-year-old boy.
Their victim was left with serious facial injuries after being repeatedly kicked and struck with a bottle.
The attack took place in the village's Buckie Road at about 21:25 on Friday. The injured boy was treated at Edinburgh Royal Infirmary.
Police have appealed for information, saying it was a "brutal and frightening attack".
The main suspect is described as white and male, about 15 or 16 years old.
He is approximately 5'10" and was wearing a dark hooded top.
Police think the attack may have been recorded on a mobile phone.
Det Con Lynn Myles said: "This was a brutal and frightening attack, which has left a 15-year-old with significant injuries.
"We are eager to trace the youths responsible for this incident, particularly the male who used a bottle as part of the assault.
"I would ask anyone who saw this incident, or recognises the description of the suspect, to contact us as soon as possible.
"I would especially appeal anyone who may have filmed this incident on a mobile device to get in touch with us and let us see this evidence."