A gondola of a Ferris wheel at the 'Highfield' Rock and Pop festival caught fire at 9 p.m. local time (1900 GMT) on Saturday night, and the fire then spread to another gondola. Both gondolas were destroyed, reports Xinhua news agency, quoting DPA.

Among the 23 injured, four were burned and one was injured from falling, while the other wounded, including emergency workers and four police officers, were receiving medical examinations in a hospital, said the local police.

The festival, attended by about 30,000 people, was interrupted for about two hours due to the fire, the police said, adding that the investigators are still looking into the cause.