U2 has delayed upcoming 360 Degrees tour dates in the U.S. until 2011 due to a back injury suffered by lead singer Bono. Concert promoter Live Nation announced the postponement on Tuesday.

U2 lead singer Bono went under the knife for emergency back surgery on Friday after injuring himself preparing for the next leg of the band’s 360 Degrees world tour. As a result of the injury and surgery, some U2 tour dates will have to be postponed.