NASHVILLE (AP) - If you shopped at a Mapco convenience store recently, your financial information may be at risk.

The Tennessean (http://goo.gl/GcmCv) is reporting that Mapco is warning that hackers may have gained access to customer debit card and credit card information.

The Brentwood-based chain says customers who made credit card or debit card purchases at certain locations during three different time periods are at risk. Company officials say customers may be vulnerable if they used cards at those stores from March 19-25, April 14-15 and April 20-21.

The locations involved Mapco Express, Mapco Mart, East Coast, Discount Food Mart, Fast Food and Fuel, Delta Express and Favorite Markets. The stores are located in Tennessee, Kentucky, Virginia, Arkansas, northern and central Alabama, northern Georgia and northern Mississippi.

Company officials say it's not clear whether any card information has been stolen.

"We regret any inconvenience this criminal act by hackers may have caused and are enhancing our information security efforts to combat future information security threats," Tony Miller, the chain's operations vice president, said in a statement. ". We have disabled the malware that was used in this incident while establishing additional safeguards designed to prevent his from happening in the future."

The hackers targeted systems that transmit card information and potentially stole financial data that could be used to make fraudulent purchases.

The company did not provide details on how many customers may be at risk. The FBI and a computer forensics company are investigating.

Mapco is urging customers to check their card balances and contact their financial institutions as soon as possible if they think their accounts have been compromised.

Customers with questions can call (877) 297-2081 for more information.