Radisson Hotels & Resorts said its computer systems have been accessed without authorization, affecting an unknown number of people. The computers were accessed between last November and May.

"While the number of potentially affected hotels involved in this incident is limited, the data accessed may have included guest information such as the name printed on a guest’s credit card or debit card, a credit or debit card number, and/or a card expiration date," Radisson said in a statement.

 

It has informed customers of the situation. It did not specify how many hotels or customers were affected but advised that all guests review their account statements and report unauthorized purchases to the bank that issued the credit card, as well as law enforcement authorities.

 

It also said that it is conducting a thorough review of the potentially affected computer systems, and has implemented additional security measures designed to prevent a recurrence and to protect the privacy of its guests.