The members of U2 were forced to abandon a gig in Berlin after Bono suffered a 'complete loss of voice' during the concert.
It happened as the band performed at Mercedes-Benz Arena for a second night, as part of the eXPERIENCE & iNNOCENCE tour.
The band had to stop after only five songs due to Bono's voice issues.
In a statement, the other three band members explained: "We're so sorry for tonight's cancellation. Bono was in great form and great voice prior to the show and we were all looking forward to the second night in Berlin, but after a few songs, he suffered a complete loss of voice.
"We don't know what has happened and we're taking medical advice."
They added that they'll offer an update 'very soon'.
The Berlin gigs marked the start of the European leg of the tour, following North American dates earlier this year.
The band is set to perform in Cologne on Tuesday, and it was not immediately clear if the gig would go ahead or not.
U2's current European tour is set to continue until early November, when the band is scheduled to perform four sold-out homecoming gigs at Dublin's 3Arena.
