Black Sabbath fans in Edmonton and Calgary will have to wait for their fix of the British rock band as a medical emergency suffered by lead singer Ozzy Osbourne has caused the band to postpone Saturday night's show at Rexall Place and Monday night’s show at the Scotiabank Saddledome.

The band announced the postponement on their Twitter and Facebook pages.

Rescheduled dates for Black Sabbath’s Alberta shows will be announced at a later time.