U2 frontman Bono has undergone emergency surgery after injuring his back during rehearsals.

The singer was admitted to a specialist neuro surgery unit in a Munich hospital, and is expected to spend the next few days there.

The operation has led to the cancellation of the opening date on the second leg of U2’s 360 Degree world tour, in Salt Lake City on June 3.

It is not clear whether Bono’s injury will affect the band’s scheduled headlining performance at the Glastonbury festival in June.

In a statement on U2.com, the band said: “Once his condition has been assessed further, a statement will be made regarding the impact on forthcoming tour dates.”

U2 manager Paul McGuinness said that they would “make plans to reinstate the dates as soon as possible”.

The Irish band's 360 Degree tour won plaudits last year for its eye-catching stage set.

(by Jason Gregory)