U2 were forced to postpone the next leg of their world tour after singer Bono injured his back, the band said tonight.
The singer underwent emergency surgery in Germany after suffering an injury while preparing for the upcoming shows in the US.
Bono, who celebrated his 50th birthday in New York earlier this month, was treated at a specialist neuro surgery unit in a Munich hospital.
"Bono will spend the next few days there, before returning home to recuperate," the band said on their website.
Promoters Live Nation said the singer's sudden injury forced the band to pull the plug on the latest U2360 degree tour launch on June 3, Salt Lake City. The event will be rearranged.
"Once his condition has been assessed further, a statement will be made regarding the impact on forthcoming tour dates," the band added.
U2's manager Paul McGuinness also posted a message to inconvenienced fans on the U2 website insisting the tour dates will be rescheduled.
"The bank were really looking forward to getting back out on the road until the emergency on Bono's back which took place in Munich today," he said.
"We were due to start rehearsals on Tuesday in Salt Lake City and get the show ready for the next leg. There were going to be some changes, and some new material.
"It's unfortunate that we're inconveniencing fans. We will make plans to reinstate the dates as soon as possible.
"Obviously it's been very disruptive for our crew as well. We have 400-plus people converging on Salt Lake City and some of those have been turned around and told to stay at home until we make our new plan. We hope to get things resolved as soon as possible."