A 19-year-old Norwich woman has been raped at the Latitude music festival in Suffolk after asking for directions.
The woman was with friends in a tent in the red area of the campsite in Henham Park, Southwold, and left at 2200 to 2230 BST on Thursday to find a toilet.
Three or four men said they would show her the way but grabbed her and raped her before running off.
The festival is set in a country estate and features bands, theatre, poetry, film, literature and dance.
Police said the woman approached the group because she believed she recognised one of the men, described as of muscular build and with a shaved head, as being a friend.
As she got closer she realised she was mistaken, but asked for directions.
'Stay with friends'
While walking, some of the group, including the man with the shaved head, left to go in another direction.
Some of the men continued to walk with the teenager and headed into a darker area with trees, where she was raped by at least one of the men.
One of the men is described as white with dark curly hair, about 5ft 7in (1.70m), of medium build, possibly in his 20s and with a London accent.
Police have urged people to stay with friends while at the event and appealed for anyone with information to contact them.
The woman, who was wearing denim jeggings, a yellow and white check shirt, a black cardigan and Wellington boots, reported the attack to festival security staff.
Police said they were liaising with the organisers and would be carrying out inquiries on the site, including viewing CCTV recordings.