A teenager is recovering in hospital after being stabbed in a cinema at The O2 Arena.
The male victim was attacked at Cineworld at the North Greenwich venue in south east London yesterday afternoon.
Police said they were called by London Ambulance Service at 2.46pm to reports of a stabbing.
Three teenage boys were detained at the scene by security staff and then arrested by police on suspicion of causing grievous bodily harm. They remain in custody.
Witnesses described up to ten police officers rushing into the arena hours before a gig for South Korean boyband ATEEZ in another part of the building as fans warned each other to stay safe.
One tweeted: “[I don’t know] what’s going on at the O2 but around 10 police officers were charging into the O2, some person got arrested near the queue and a helicopter circulated and landed near the O2.”
Another said: “Anyone know what was just happening at The O2 arena with all the police running around?”
A third added: “Helicopter, undercover police car and another police car just rushed to the London ATEEZ concert… HELLO??”
The Metropolitan Police said in a statement: “Officers attended. A teenage male was found with stab wounds.
He was treated at the scene by paramedics before being taken to hospital. His condition has been assessed as non life-threatening.
“A crime scene has been put in place and enquiries continue.”
A spokesman for The O2 said after the incident: “This afternoon there was an altercation between a group of individuals in Cineworld at The O2, which resulted in one of the individuals requiring medical attention from the emergency services.
“Cineworld at The O2 will remain closed for the rest of the day.
“The rest of The O2, including outlet shopping, bars and restaurants, and attractions remain open. Tonight’s arena event is going ahead as planned.”
Cineworld at the O2 is now reopened.