The band U2 ended a concert in Berlin on Saturday partway through its performance after its lead singer, Bono, said he had lost his voice.

The band had just finished playing the song “Beautiful Day,” with Bono visibly struggling to belt out the lyrics, when he halted the concert, apologized to the audience and said the band “cannot go on.”

In a statement released after the show, which was part of the band’s European Experience + Innocence tour that is set to run through November, the band apologized.

“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,” the statement said.