The incident occurred on Saturday evening
Four men have been stabbed during a fight at a music festival in East London.
Two of the men attacked at Garage Nation festival in Hainault Forest Country Park on Saturday were airlifted to hospital.
One of the men, a 26-year-old, may have suffered life-changing injuries, the Metropolitan Police has confirmed.
Police believe that the men were stabbed when a fight broke out in the VIP area, before a group of male suspects made their escape from the entrance.
According to the Met, the other victims had “stab and slash” wounds.
The second victim airlifted to hospital was a 22-year-old, who sustained non life-threatening injuries.
A third man was taken to an east London hospital with a less serious stab wound and he has since left hospital.
The fourth man was treated at the scene by paramedics and left before police arrived.
Police were called at 19:35 on Saturday evening and London Ambulance Service and London’s Air Ambulance also attended the scene.
Eyewitness Mel Dee told the BBC how she saw one of the victims being attacked across the back.
“We saw him go towards someone in quite an aggressive manner. Then he jolted back,” she said.
“They’d slit his back, slashed him. It was very deep, he was fuming.”
The 21-year-old added: “All of a sudden he’d ran towards whoever else it was and soon there were 15 of them. Other knives were pulled out.
“I could see people punching – arms flying everywhere.”
A spokesman from Garage Nation’s promoters said: “We run a strict four-stage policy search regime. The security was procured and agreed in line with the planning that has been ongoing for 12 months.”