WEST DES MOINES, Iowa (AP) — An Iowa-based grocery store chain is warning customers about what it says is a security incident involving payment card systems.

Hy-Vee said in a news release Wednesday that it launched an investigation after it detected unauthorized activity on some of its payment processing systems — activity that the company thinks has stopped.

The investigation focused on card payments at Hy-vee restaurants, fuel pumps and drive-thru coffee shops. Company officials think the problem doesn't involve payments systems used inside its grocery stores, drugstores and convenience stores. They use encryption technology for processing card transactions.

Hy-vee intends to notify customers when it can share specific timeframes and locations that may have been involved.

The company is based in West Des Moines and operates more than 240 retail stores in eight Midwestern states: Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, South Dakota and Wisconsin.