Kimpton Hotels and Restaurants advised guests of a possible breach.

In a statement released July 26, the chain of 60-plus hotels and 70-plus restaurants in 32 U.S. cities, said it was “recently made aware of a report of unauthorized charges occurring on cards that were previously used legitimately at Kimpton properties.”

Kimpton has hired a computer security firm to find out if personal information of guests was exposed or its internal network hacked.

It is advising recent guests to “closely monitor their payment card account statements” and quickly contact their banks if they see suspicious charges.

No information has yet been released on the number of guests whose data might have been exposed.

On his blog, security researcher Brian Krebs said this incident follows a pattern of other recent attacks on hotel chains, as well as Target and Home Depot, where criminals plant malicious software on point-of-sale devices via hacked remote administration tools.