Hy-Vee is asking customers to double-check their payment card statements, after it detected what it's calling a " security incident."

The grocer, which has eight Sioux Falls locations, said Wednesday it is conducting an investigation after detecting unauthorized activity on some of its payment processing systems.

The incident is centered on card transactions at Hy-Vee fuel pumps, drive-through coffee shops and restaurant locations such as Market Grilles and Market Grille Expresses.

Transactions at Hy-Vee's in-store check-out lanes, convenience stores, drug stores floral departments and wine & spirit shops use a different system and technology and aren't involved, Hy-Vee said.

"We believe the actions we have taken have stopped the unauthorized activity on our payment processing systems," Hy-Vee said.

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The grocer is conducting an investigation with the help of cybersecurity firms and has notified federal law enforcement and payment networks.

"Because the investigation is in its earliest stages, we do not have any additional details to provide at this time," said Hy-Vee in its statement. "We will provide notification to our customers as we get further clarity about the specific time frames and locations that may have been involved."

Hy-Vee recommends customers closely monitor their payment card statements and check with their financial institutions if they see any unauthorized activity.