MIAMI -- Pop star Justin Bieber attended a mediation session in Miami in a lawsuit filed by a photographer who says he was roughed up by the singer's security.

Lawyers say Bieber spent about five hours Tuesday behind closed doors at a law firm with mediator David Gersten, a former judge.

Photographer Jeffrey Binion seeks unspecified damages in the 2013 lawsuit claiming he was assaulted by a Bieber bodyguard outside a recording studio. Binion's attorney declined to say whether a settlement is near.

The 21-year-old Bieber has had several run-ins with celebrity photographers.

While in Miami, Bieber appeared at the electronic Ultra Music Festival and sang with Ariana Grande at her concert Saturday night.

Last summer, Bieber pleaded guilty to reckless driving and resisting arrest in a Miami Beach incident.