Police are investigating a report of a serious sexual assault on a woman at the Latitude festival.

Suffolk constabulary said the attack had allegedly occurred in the red camping area at Henham Park in Southwold on Saturday between 10pm and 11pm.

The force said specially trained officers were looking after the woman, whose age has not been revealed, and the investigation was continuing.

Police advised festivalgoers to stick with their friends and “look out for each other”. They added: “Be careful. Festivals give you the opportunity to meet new friends but going off alone with people who you’ve just met may lead you into situations you don’t want to be in.

“Remember no means no. There is safety in groups. Set up camp near friends, make friends with your neighbours and learn the layout of the site so you can find what you need – toilets, stewards etc, without getting lost. You can always ask staff for help with directions or anything else you may need.”

This year’s four-day festival, which ended on Sunday and attracts about 40,000 people, was headlined by Lana Del Rey, Stereophonics and George Ezra.

Animal rights organisations and activists have accused the festival organisers of cruelty for dyeing a flock of sheep pink as part of a marketing campaign.