AB Acquisition LLC, the Boise, Idaho company which operates Malvern-based Acme Markets and several other regional grocery store chains across the United States employing some 115,000 people, 18,000 in the Delaware Valley, announced Thursday it had recently learned of an unlawful intrusion to obtain credit and debit card payment information in some of its stores.

The appropriate federal law enforcement authorities have been notified, and AB Acquisition is working closely with its third party IT services provider to better understand the nature and scope of the incident.

Third-party data forensics experts have been brought in on an ongoing investigation. AB Acquisition has not determined that any cardholder data was in fact stolen, and currently it has no evidence of any misuse of any such data.

Based on the latest information from the ongoing investigation, it appears that the period of unauthorized access may have started on June 22, 2014 (at the earliest) and ended on July 17, 2014 (at the latest).

The company believes all ACME Markets in Pennsylvania, Maryland, Delaware and New Jersey were impacted by this incident.

AB Acquisition believes that the intrusion has been contained and is confident that its customers can safely use their credit and debit cards in its stores.

In a press release Thursday afternoon the company promised more information about the breach would be available on acmemarkets.com within 24 hours.