NASHVILLE, Tenn. - Lady Gaga has canceled the rest of her tour dates due to a hip injury.

A Wednesday news release from Live Nation Global Touring says Lady Gaga has a tear in her right hip that will require surgery to repair, followed by a recovery period.

The pop star had 21 dates through March 20 remaining on her "Born This Way Ball" tour schedule. She postponed four dates on Tuesday after telling fans in a tweet she'd hurt herself some time ago, but hid the injury from her staff. Over the last month, the injury became worse and she said she was unable to walk following a performance Monday in Montreal.

Fans who have already bought tickets will receive a refund.