R&B star August Alsina became embroiled in a nasty altercation backstage at a concert in St. Louis, Missouri on Saturday (17Jan15) after clashing with the show's promoter.

The No Love singer and his entourage were caught on camera being confronted by event organiser Loose Cannon Slim behind the scenes at the Chaifetz Arena after Alsina reportedly held up the State Of Emergency 2 gig, which was ironically staged to promote non-violence.

Video footage obtained by Tmz.com shows the two parties in a heated exchange, before one of Alsina's pals appears to lunge at Slim, sparking a big fight.

Rapper Fabolous, who had been a part of the show line-up, was also filmed backstage, watching the brawl unfold from afar.

Neither Alsina nor Slim had commented on the backstage clash as Wenn went to press.

2 Chainz, Migos and Yo Gotti also performed during the gig, which benefitted the local Put Down the Pistol anti-gun programme.