According to Billboard… the rap duo Run the Jewels was attacked onstage Monday during a performance at South by Southwest in Austin, Texas, briefly interrupting their set at the Spotify house event.

Radio.com reports… It’s not clear what exactly happened or why, but mid-set an unidentified man came onstage and approached the pair, attempting to take a swing at El-P. His partner, Killer Mike, spotted the would-be assailant and intercepted him, while the band’s crew members intervened and got him out of there.

Run the Jewels then continued on with their set.