Irish rockers U2 cut short a performance in Germany as lead singer Bono bizarrely suffered a "complete loss of voice".

It's still unknown the mysterious reason for Bono's sudden vocal chord issue.

“We don’t know what has happened and we’re taking medical advice,” said a statement signed by band members Adam Clayton, Larry Mullen, and The Edge.

“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,” the statement added.

“‘I’ve lost my voice and I don’t know what to do,’ Bono said before the show was halted.” This literally made me tear up. His voice means so much to me. He’ll be okay. But to think of not having that voice. I can’t. Get well soon, Hero! https://t.co/w2l1VJgbpk

— Ava DuVernay (@ava) September 2, 2018

“As always, we appreciate our audience’s understanding and all our fans’ support in Berlin and those who traveled from afar. We will update you very soon," it concluded.

Read more: Could this be the end of U2 after 40 years?

The four-piece band had performed a stellar full set the night previous.

U2 fan site Atu2 stated that Bono attempted to sing hit song "Beautiful Day" before being forced to leave the stage. Moments earlier, he had visibly struggled to serenade the audience with "Red Flag Day". 

The Irish Independent notes that at this moment, he told the crowd he couldn't continue before rushing off-stage.

According to the New York Times, Bono told had the crowd moments earlier, “I’ve lost my voice and I don’t know what to do..I was singing like a bird 10 minutes ago. I’m sure it will pass.”

It appears that the 58-year-old has never had to halt a performance before due to vocal issues. 

Get well soon, Bono! 🙏@U2 #u2eitour pic.twitter.com/aOXlgTf0FN

— Mercedes-Benz Arena (@MBArenaBerlin) September 1, 2018

Actress Ashley Judd, who happened to be at the show, posted footage of Bono’s performance on Twitter, commending the singer and reminding everyone that he's not invincible.

The power of #bono voice before it surprised him in #Berlin and left him abruptly...he was singing his guts out (per usual). @u2 @U2eiTour The crowd so felt for him as he with surrender was obviously powerless and vulnerable. He’s real and he’s human, too, like we all are. pic.twitter.com/f0Tl3hhuA2

— ashley judd (@AshleyJudd) September 1, 2018

The band are due to perform next on September 10th.

Read more: Plans for U2 museum in Dublin blocked amid 'serious concerns'