The Tomorrowland Unite Spain festival is currently underway in Barcelona.
Around 22,000 people had to be evacuated from the festival after a fire broke out on the main stage.
According to Spanish newspaper El Pais, the blaze apparently broke out after a pyrotechnic element malfunctioned.
No injuries have been reported so far.
Fans have been posting footage of the blaze online.
DJ Steve Aoki had been due to perform on the stage at the event when the fire began.