Massive flames engulfed the main stage at a popular EDM music festival, resulting in the evacuation more than 22,000 attendees Saturday night.

The Mirror reports the blaze broke out at Parc de Can Zam during Barcelona’s Tomorrowland Unite, just hours before headliner Steve Aoki was set to perform. Concert-goers captured the terrifying moment on video, showing a small fire breaking out near a stack of speakers before taking over the left side of the stage. Watch them below.

Festival organizers released a statement on Facebook, stating the fire was caused by “a technical malfunction.” According to the Mirror, there have been several reports that on-stage pyrotechnics were to blame; however, nothing has been confirmed as Spanish authorities are still investigating.

No serious injuries have been reported as a result of the fire. Some attendees were treated for anxiety following the evacuation.

Firefighters were able to control the fire in about half an hour, but warned organizers about the stage’s potential collapse. Tomorrowland Unite ended about five hours early because of the blaze, leading several attendees to request refunds on social media.

The actual Tomorrowland festival takes place in Boom, Belgium, and is live streamed in cities across the world, including Dubai, Malta, and Incheon Metropolitan City in South Korea.