Over 30 people were injured when two gondolas of a Ferris wheel caught fire on Saturday night (August 17) at Highfield Festival in Leipzig, Germany, reports German news broadcaster Deutsche Welle. While most injuries were mild cases of smoke inhalation, four people suffered burns and one sustained injuries from a fall. Police said that the cause of the fire was initially unclear.

“Those affected are receiving treatment and are doing well considering the circumstances,” Highfield Festival organizers said in a statement. “We are in close coordination with the fire brigade, the police, and the rescue and medical services. We will cordon off the ferris wheel accordingly and then continue operations as planned.”

The fire reportedly broke out in one Ferris wheel gondola car and spread to a neighboring one around 9 p.m. local time during German rapper Ski Aggu’s set. “I’m absolutely shocked and upset about the Ferris wheel fire during my show at Highfield,” Aggu posted on Instagram afterwards. “I was only told through my earpiece that I should not stop the show under any circumstances, but should initially continue to talk with you so avoid mass panic. The priority was to prevent the situation from escalating any further. Fortunately, that worked.”

Highfield Festival is one of Germany’s biggest music festivals, with around 30,000 attendees. This year’s lineup featured headliners Rise Against (whose set was delayed due to the Ferris wheel fire), Macklemore, and Peter Fox, with other performers such as Flogging Molly, Less Than Jake, the Kooks, Mando Daio, Marsimoto, Cro, and more.