The Mayor of London, Sadiq Khan, has expressed sadness over a crush outside a South London venue hosting a concert by Nigerian Afrobeats singer Asake on Thursday.

Emergency teams were called to the O2 Academy in Brixton at 9:35 pm (2135 GMT) on Thursday following reports “that a large number of people were attempting to force entry to the venue”.

Police, ambulance crews, and fire brigade officers arrived to find numerous people with injuries.

According to channels tv.com eight people were taken to hospital by ambulance while two “less seriously injured” were treated at the scene.

Reacting to the incident in a tweet on his verified Twitter page on Friday, Khan said an urgent investigation is underway.

His post read, “My thoughts are with all those affected by the awful incident at Brixton Academy. Eight people were taken to the hospital, with four in critical condition.

“An urgent investigation is underway and I remain in close contact with the Met Commissioner since last night. I’m heartbroken that this could happen to young Londoners enjoying a night out in our city and urge anyone with any information to contact the police on 101.

“I won’t rest until we have the answers their loved ones and the local community need and deserve.”

The incident occurred during the last of three sold-out performances at the venue by singer-songwriter Asake.

The gig was cancelled midway through the performance. Reports said an irate crowd was told that up to 3,000 people had tried to break through the doors, with some succeeding, and that police had ordered the show to stop.