NEW YORK — Home Depot may be the latest retailer to suffer a major credit card data breach.

The Atlanta-based home improvement retailer told The Associated Press Tuesday that it is working with both banks and law enforcement to investigate “unusual activity” that would point to a hack.

“Protecting our customers’ information is something we take extremely seriously, and we are aggressively gathering facts at this point while working to protect customers,” said Paula Drake, a spokeswoman at Home Depot, declining to elaborate. She said the retailer would notify customers immediately if it confirms a breach.

Shares of Home Depot Inc. fell $1.88, or 2 percent, to close at $91.15.

Hackers have broken security walls for many retailers in recent months, including Target, grocery store chain Supervalu, P.F. Chang’s and the thrift store operations of Goodwill. The rash of breaches has rattled shoppers’ confidence in the security of their personal data and pushed retailers, banks and card companies to increase security by speeding the adoption of microchips into U.S. credit and debit cards.

Supports say chip cards are safer, because unlike magnetic strip cards that transfer a credit card number when they are swiped at a point-of-sale terminal, chip cards use a one-time code that moves between the chip and the retailer’s register. The result is a transfer of data that is useless to anyone except the parties involved. Chip cards are also nearly impossible to copy, experts say.

The possible data breach at Home Depot was first reported by Brian Krebs of Krebs on Security, a website that focuses on cybersecurity. Krebs said multiple banks reported “evidence that Home Depot stores may be the source of a massive new batch of stolen credit and debit cards” that went on sale on the black market earlier Tuesday.