(CBC.ca) - Green Day has postponed the first three dates of its upcoming tour and cancelled a fourth show due to illness, the band announced Sunday.

Concerts will be rescheduled in St. Louis, Chicago and Detroit, and a fourth concert in Toronto is being cancelled. Tickets will be refunded, the band said.

"We're so sad to announce we have to postpone three shows and cancel Toronto," said the band. "Many of us have been battling this infection for days on end to be ready, and it just got the best of us."