Hershey Park, a popular resort and amusement park in Hershey, Pa. has hired a security firm to investigate reports from multiple financial institutions about a possible credit card breach, KrebsOnSecurity has learned.

Contacted after reports by several financial institutions about a pattern of fraudulent charges on customer cards that trace back to Hershey properties, the company says it is investigating.

“We have received reports from some of our guests that fraud charges appeared on their payment cards after they visited our property,” said Kathleen McGraw, director of communications for Hershey Entertainment and Resorts Company.

“We take reports like this very seriously,” McGraw continued. “While our company does have security measures in place designed to prevent unauthorized access to our network, we immediately began to investigate our system for signs of an issue and engaged an external computer security firm to assist us. The investigation is ongoing.”

Sources at three financial institutions say they have detected a pattern of fraudulent activity on customer cards that were used at Hershey properties in Pennsylvania between mid-March and late May 2015. According to the banks, the cards were used at a variety of Hershey locations, including food and beverage outlets, ticketing stations and the Hershey Lodge.