Nigerian Afrobeats star Asake was forced to cancel his sold-out show at O2 Academy Brixton midway through after crowds of people, many of whom did not have tickets, attempted to gain access.
According to reports, ticketless fans tried to breach the venue doors, forcing the sold-out show to stop halfway through on Thursday night.
Four people were critically injured and four others were hospitalised following a crush at the concert venue in south London, police said.
Police and other emergency services were called to the O2 Academy in Brixton at 21:35 pm (2135 GMT) following reports “that a large number of people were attempting to force entry to the venue.
“They arrived to find a number of people with injuries believed to have been caused by crushing.
“Detectives are investigating the circumstances which led to four people sustaining critical injuries,” the Metropolitan police said.
Two “less seriously injured” people were treated at the scene while the eight others were taken to hospital by ambulance.