Radisson Hotels said a data breach compromised some information for Radisson Rewards members, but said credit card and password information was safe. The company did urge members to monitor their accounts and be careful of “phishing” attempts by hackers to pose as the company to extract more personal information from guests.

RADISSON HOTELS IS warning its Radisson Rewards members to look out for suspicious behavior on their accounts following a data breach that compromised some member information. No other guest other credit card or password information was put in jeopardy.

Radisson found the leak on Oct. 1, saying an unauthorized party gained access to some member’s name, address (including country of residence), email address, and in some cases, company name, phone number, Radisson Rewards member number and any frequent flyer numbers on file. The company revoked the unauthorized access and flagged all affected accounts to monitor for suspicious behavior.

Radisson also warned members to look out for attempts to “social engineer” attempts to get more information.

“You should also be aware that third parties may claim to be Radisson Rewards and attempt to gather personal information by deception (known as ‘phishing’),” the company said. The phishing can include links to fake websites. “Radisson Rewards will not ask for your password or user information to be provided in an e-mail.”

Affected members have already been e-mailed notifications. However, online cyber security expert Graham Cluley had some concerns about Radisson’s reaction to the breach. For example, the company is not specifying the number of members affected, possibly to prevent further panic.

“Secondly, it’s disappointing that there’s no indication of how the breach might have occurred,” Cluley wrote in an online article. “Was there a vulnerability on the Radisson Rewards website that has now been fixed? Were some accounts compromised because the hackers were able to break in using credentials that perhaps they scooped up in an earlier attack against a different website? We don’t know, because Radisson isn’t sharing any details.”

Last year saw several data breaches at major hotel chains. In May Sabre reported a breach in its online reservation system that did compromise payment card information.  Around the same time Hard Rock Hotel properties reported a breach in its reservation system as well.