The loyalty program Air Miles says that it is temporarily suspending the ability to redeem “Cash Miles” in stores after the company realized “Cash Miles have been stolen” in a “small number of in-store Air Miles Cash transactions.”

Cash Miles can still be redeemed for e-vouchers that can be spent at stores including Staples, Starbucks, Cineplex and the Bay, the company said in a statement posted online.

“The personal information of all Collectors remains protected and has not been compromised,” the statement goes on. “We are working diligently to resolve the situation and have already contacted our retail Partners, the police and the Canadian Anti-Fraud Centre.”

Air Miles says it is advising clients to “protect the security of your AIR MILES Account by maintaining the confidentiality of your Collector and PIN number.”