The Black Sabbath star was among the performers on the bill for his festival in Riviera Maya in May (15), but he has now axed the event due to an unspecified medical scare.

The promoters behind Ozzfiesta have confirmed Osbourne is set for an operation and needs at least a month to recover, but no further details about his condition have been given.

Ozzfiesta promoters Cool Breeze Concerts say in a statement, "Like you, we were very excited about the event. However, Ozzy is having surgery, scheduled for May, following his South American tour. He requires at least four weeks of recovery time. We are very disappointed that we need to cancel... We apologise for any inconvenience and hope that you understand the circumstances surrounding the cancellation."

Osbourne is currently on tour in South America. Those dates are not believed to have been affected.

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Rolling Stone: Ozzy Osbourne Needs Surgery, Cancels Ozzfiesta | Rolling Stone