Surveillance video has surfaced of Solange Knowles, a singer who's famous for being Beyoncé Knowles' sister, attacking Jay Z in a hotel elevator last week.

The altercation went down at a Met Gala after-party last week in New York.

In the surveillance video, you see Jay Z, Beyoncé, Solange and a bodyguard get on the elevator. Solange immediately gets in Jay Z's face and starts hitting him.

The bodyguard grabs Solange and restrains her, then hits the emergency stop button in between floors.

The altercation lasted nearly four minutes, TMZ reported.

Source: Free Beer & Hot Wings