Thousands attended this year's festival at Balado
A man stabbed eleven times at the T in the Park music festival is said to be making "good progress" in hospital.
It has emerged that the 22-year-old had gone to help a female friend in the early hours of Sunday morning after she had been accosted by two men.
Police revealed the victim, from Glasgow, had been stabbed eight times in the body and three in the head.
Detectives said they had recovered good forensic evidence and were attempting to trace the two men.
In total, 67 people were arrested at the festival - 30 were due in court on Monday on drugs and theft charges, and three people were charged with assault.
Police said the stabbing had been the most serious incident.
The victim was attacked at the T in the Park campsite at about 0045 BST on Sunday.
Police earlier described his injuries as "horrific". He is being treated at Ninewells Hospital in Dundee.
Detectives have managed to speak to the man and have also taken statements from "a large number" of witnesses.
Forensic examinations of the attack scene have been completed - but the results are not due for a number of days.
Det Ch Insp Bruce Kerr, from Tayside Police, told BBC Radio's Good Morning Scotland programme: "He was an innocent victim.
"He went to intervene with the two males who were accosting one of his female friends and they just set about him and he was stabbed 11 times, eight to the body and three to the head."
Police have circulated a description of the suspects and urged any revellers who witnessed anything to contact them.
The first suspect was described as white, in his late teens, about 6ft 1in tall, of skinny build, with short, dark brown hair. He was wearing a white tracksuit top.
The second was also said to be white, about 5ft 8in and of medium build, with short, dark brown "mullet-style" hair. He was wearing a red tracksuit top.
Their clothing was likely to have been blood-stained following the attack.
In another incident, emergency services were called at about 1150 BST on Sunday when Derek Boyle, 32, from Paisley, was found by friends in his tent after becoming ill.
Medical staff tried to save him but he was later pronounced dead at the festival's on-site hospital.
Festival director Geoff Ellis said: "In T in the Park's 15-year history this is the first time we have had a death on-site and we are shocked and saddened to hear the news. Our thoughts are with the family at this time."
Of the stabbing, he added: "It was isolated, but serious. Fortunately we have a great medical team and a medical hospital on site and we were able to treat him very quickly and he's in a stable condition.
"Hopefully the police will catch the people responsible."
About 80,000 music fans attended the three-day event, staged in Perth and Kinross.
Event commander, Ch Supt Matt Hamilton, said that the large majority of people were well behaved.
He said: "It is a credit to the tens of thousands that flocked to Balado this weekend, and to the various agencies that make this terrific event possible, that we can report that incidents of crime and disorder were very low.
"Overwhelmingly, people have been here to enjoy a friendly, party atmosphere and I am happy to report that in its 15th year, T in the Park has without doubt been a huge success again.
"Our officers have told me that they have experienced a good-natured crowd on each day that has been intent on enjoying themselves. Tayside Police were happy to play their part in ensuring that happened."