An unknown number of Hy-Vee customers may have had their credit card data compromised, the grocer that operates in Lawrence warned on Wednesday.

Hy-Vee is investigating a “security incident” at its credit card readers at Hy-Vee-owned gas pumps, restaurants and drive-thru coffee shops. The Iowa-based retailer said it recently detected unauthorized activity on some of the company’s payment card networks. The company contacted federal law enforcement officials and has started its own investigation with the help of a cybersecurity company.

Hy-Vee didn’t say what type of payment card data may have been compromised or how many accounts may have been affected. The company said it does not currently believe the incident involved transactions made inside their grocery stores, pharmacies or convenience stores, although pay-at-the-pump transactions at convenience stores may have been compromised.

Hy-Vee operates a convenience store and fuel pumps in west Lawrence and also has a restaurant connected to its grocery store at Clinton Parkway and Kasold Drive.

The company said its investigation was in its early stages. It plans to provide notification to customers about specific time frames and locations that may have been involved as those details become available.