Two girls suffered minor injuries after rapper Fetty Wap jumped off stage and into the crowd at the Billboard Hot 100 festival on Long Island.
Newsday reports the girls became trapped under a fence on Sunday afternoon when the crowd rushed the stage.
Wap is one of two dozen artists performing at the Nikon at Jones Beach Theatre. Others include Justin Bieber, Nicki Minaj and Lil Wayne.
More than 1,000 fans were in the audience as a group pushed forward to take photos and video of the entertainer.
The newspaper says the girls were treated by medics backstage.
Wap returned to the stage minutes later and apologised before continuing with the performance.
Representatives for Wap, whose real name is Freddy Maxwell, did not immediately respond to an email seeking comment.
