One person has been injured after fights broke out at an Alkaline gig in Brixton.
Officers dealt with “disorder” both inside the O2 Academy Brixton and outside the venue, the Metropolitan Police have told Newsbeat.
There have been no reports of any arrests.
Witnesses have shared photos and videos on social media, with many suggesting groups of people were trying to force their way into the venue.
Along with dancehall star Alkaline, who is from Jamaica, the gig was set to feature a performance from Chipmunk.
A spokesperson for the O2 Academy Brixton from the Academy Music Group said: “Police were in attendance at O2 Academy Brixton to assist with external crowd control at approximately 8.15pm on Sunday 23 April.
“No arrests were made or injuries reported following advice by the local authorities to cancel the live performance by the artist, Alkaline, in the interest of public safety.
“Academy Music Group would like to thank the police and response units, staff, security and all performers, who acted swiftly and professionally to diffuse the situation outside as quickly as possible with no issues inside the venue.
“With sincere apologies to all ticket purchasers, customers are advised to please contact their point of purchase in the first instance for further information.”
When he toured the UK last year, a number of Alkaline’s gigs were cancelled over security fears, including one in Sparkhill, the Birmingham Mail reported at the time.
“At the request of West Midlands Police , it was agreed the event should not go ahead due to specific and credible information received by police, which raised concerns for public safety,” said a police spokesperson in June 2016.
It’s being reported that the gig had to be abandoned before Alkaline ever took to the stage.
It’s not yet clear if a new concert will be rescheduled for a future date.