The organisers of an arts and music festival are appealing for witnesses after a woman was allegedly raped in a tent.
Festival-goers at the Secret Garden Party in Cambridge were being asked if they heard a woman screaming in the middle of the night following reports of the attack in the early hours of Friday.
Posters were reportedly put up around the site at Abbots Ripon in Huntingdon asking for help from anyone who was at the three-day festival.
One said: "'Police are appealing for any witnesses who might have heard screaming in the early hours of Friday morning, or seen/heard anything suspicious.
"Officers are warning Gardeners to be extremely vigilant and take care if deciding to take any substances."
A statement on the festival's website said: "A woman has alleged that she was raped in the early hours of Friday, July 24 in one of the tented areas of the Secret Garden Party site.
"Police have appealed for any witnesses who might have seen or heard anything suspicious in the early hours of Friday morning to contact a police officer on-site, visit the welfare tent, call 101 or Crimestoppers anonymously on 0800 555 111.
"The Secret Garden Party team are working closely with the police to assist them with their investigation."
Cambridgeshire Police were unavailable for comment.