In response to the Hannaford Bros. Co. data security breach, local banks and at least one other supermarket chain are working to protect their customers from fraud.

The Maine Association of Community Banks reports no uptick in fraudulent use of cards issued by its member banks, but banks have been reporting scams in which people posing as bank representatives have called and e-mailed customers and asked for personal identification and financial information.

“No financial institution will ever ask for that information over e-mail or telephone,” said Chris Pinkham, president of the Maine Association of Community Banks.

Financial institutions in the Northeast and Florida have reported floods of customer inquiries after Hannaford announced Monday that hackers had accessed 4.2 million credit and debit card numbers between Dec. 7 and March 10. At least 1,800 card numbers have been used fraudulently, according to the Scarborough-based grocery chain, which has numerous stores in Maine. Hannaford is now leaving it up to financial institutions to handle reports of suspicious or fraudulent activity. Credit card companies and banks are carefully monitoring their systems.

Lynne Woodman, spokeswoman for Cleveland-based KeyBank, cautioned customers to monitor their credit and debit card account statements vigilantly.

“Nobody knows your account like you do. When you see a charge and think, ‘That’s odd, I don’t usually shop there,’ you’re going to notice that before anyone else,” Woodman said Wednesday. Customers who notice suspicious activity should call their bank or credit card company immediately.

Bangor Savings Bank is issuing new cards to any customer who makes the request. Senior Vice President Yellow Light Breen said the bank has at least 20,000 customers whose cards were in Hannaford’s database and available to hackers, but none has reported fraudulent use, Breen said. The bank has decided that replacing every exposed card would be inconvenient to customers, Breen said. It would also be costly.

Shaw’s supermarket spokeswoman Judy Chong said in light of the Hannaford security breach, the company is continuing its constant supervision of its security system.

“The security and personal information of our associates and customers are a top priority for us,” Chong said Wednesday. “We consistently perform checks and monitor and examine our system.”