Indigo Books & Music Inc. says it is dealing with what it calls a "cybersecurity incident" that has affected online customer orders.
Toronto-based Indigo said in a release Wednesday that it hopes to have its systems back online as soon as possible.
In the meantime, the company says it can process orders paid for by cash in its stores.
Indigo says it temporarily can't process electronic payments, accept gift cards or deal with returns.
No other details of the cybersecurity problem were released.
The company was dealing with customer questions about the service outage on social media.
"Hi there! At this time, you may experience delays with part or all of your order. We apologize for the inconvenience," Indigo said in a reply to a customer question on Twitter.