Detectives were today investigating two attempted murders in the final hours of the T in the Park festival.
Two 20-year-old men were found with serious abdominal injuries on a walkway between the main arena and the campsite at around 11.50pm last night.
They were taken to Ninewells Hospital in Dundee where their condition was described as serious but stable, police said.
Headline act Kasabian brought the three-day extravaganza to a close on the main stage last night before fireworks filled the air.
Detective Inspector Steve Bissett, of Tayside Police, said revellers may have witnessed something as they left the arena which could help the inquiry.
He said: "This has been a particularly disturbing incident where two men have sustained very serious injuries.
"This was the time when the majority of campers were making their way back to the campsite following the closure of the arena entertainment.
"It's possible some campers may have captured vital images of the incident on cameras or mobile phones, and a number of others will have witnessed the assault.
"I would urge anyone who witnessed these incidents take place, or anyone who may have photographs or footage of the incident, to get in touch with us."
Police said three men were helping with inquiries.
The area where the incident took place was cordoned off while officers and forensic teams examined the scene.
In a separate incident, a 19-year-old man suffered a serious head injury after accidentally falling around 6ft from a flag pole in the main arena which it is believed he climbed just after 10pm last night.
He was taken to Ninewells Hospital, where he was in a critical condition today.
Organisers said 85,000 people came to Balado Air Field in Kinross-shire for the festival, now in its 17th year.
The rain clouds that showered festival-goers on Saturday cleared yesterday, leaving the capacity crowd to enjoy the music in the sunshine.
Earlier yesterday, French DJ David Guetta wowed the crowd with hits including Sexy Chick and Memories accompanied by two giant dancing robots.
And US rapper Jay-Z played to a capacity crowd on the main stage.
He thanked people for "making me feel at home", telling them they were "too kind".
He also led a moving tribute to Notorious BIG, Tupac Shakur and Jam Master Jay, playing his hit Hard Knock Life in their memory.
They topped one of the most eclectic line-ups in the festival's history, with acts including Eminem, Muse, The Prodigy and Black Eyed Peas also taking to the stage.
The event was tinged with sadness after the death of 24-year-old old David Catto, from Stonehaven, who collapsed after leaving the main stage area on Friday.
Festival director Geoff Ellis said his death was a "tragedy" and said his condolences were with the young man's family.
A woman in her 20s was allegedly knocked to the ground and sexually assaulted near the bus parking area on Saturday night.
Tayside Police said her male attacker was disturbed by two women who were walking past.
The force appealed for witnesses.
Last night, police had arrested 56 people over the course of the event, with the number of people detained 10% down on last year.
Chief Superintendent Craig Suttie said: "Every year we have visitors from police forces across the UK who come to take back learning points from the way that we police T in the Park, and the exceptional partnership working that is carried out at the festival."
By 7pm yesterday, 608 people had been seen at the hospital tent and 19 were taken off the site for further treatment.