LONDON

Four people were in critical condition after “a large number of people attempted to force entry” to O2 Academy in southwest London Thursday evening, British police said Friday.

“Detectives are investigating the circumstances which led to four people sustaining critical injuries in Brixton,” a statement from Metropolitan Police said.

“Officers, London Ambulance Service (LAS) and London Fire Brigade attended and found a number of people with injuries believed to have been caused by crushing.”

The statement said that eight people were taken to hospital, “four of whom remain in a critical condition.” Other less seriously injured people were treated at the scene.

The incident took place after the start of a gig by Nigerian pop singer Asake. The event was canceled after the incident.

“This is an extremely upsetting incident which has left four people critically ill in hospital. My thoughts and prayers are with them and their families,” Commander Ade Adelekan from Met Police said.

“A police investigation has been launched, and it will be as thorough and as forensic as necessary to establish exactly what happened last night,” Adelekan added.