Whitney Bank Louisiana said Monday that it deactivated 7,100 debit cards over the weekend after discovering that ATMs at some of its branches had skimmers — devices that capture debit card and personal identification numbers — attached to them.

The bank detected unauthorized activity at several ATMs on Saturday evening involving customers’ debit cards, according to a news release. The bank contacted law enforcement agencies and examined all of its ATMs, removing any illegal devices, according to the release.

Customers in Baton Rouge, New Orleans, Jefferson Parish and St. Tammany Parish were affected, but Whitney spokesman Paul Maxwell stressed that the incident is part of a broader scheme along the Interstate 10 corridor. Theoretically, any customer using a Whitney Bank debit card at any ATM fitted with a skimming device could be victimized, he said.

“That’s why we reissued cards, regardless of whether we saw immediate signs of fraud,’’ Maxwell said in an email.

The bank assumes responsibility and customers won’t incur any losses, the news release said. Whitney is directly notifying customers who were affected.

Abita Springs resident Kace Nielsen is one Whitney customer who was affected by the fraud, which he discovered Sunday morning when looking at his account. He noticed an ATM withdrawal for $502.50 made from Slidell.

The $2.50 was an ATM fee.

“I hadn’t been to Slidell in over a year,’’ he said.

Nielsen, who is a firefighter in Hammond, said one of his co-workers also was hit and lost nearly $2,000.

Nielsen immediately canceled his card and called the bank first thing Monday morning. By Monday afternoon, the missing money had been replaced, he said.

The U.S. Secret Service is investigating a number of cases of ATM thefts in major cities along the Interstate 10 corridor, Nick Manale of the State Police confirmed Monday.

Skimmers are devices that can read numbers from ATM cards. Whitney described the device as a plastic mold and metal plate attached to ATM card receptors that capture card numbers and personal identification numbers.

The incident is not a breach of its system, Whitney said, adding that this type of fraud doesn’t compromise customers’ bank account information. It’s used to get debit card numbers and cash.

Whitney deactivated and reissued cards as a precaution, according to the bank, and is monitoring ATMs and ATM transactions in Louisiana for attempted fraud.

As an added measure to protect customers, the bank has initiated additional ATM security in Texas, Mississippi, Alabama and Florida.

The Secret Service suspects the fraud is the work of a group of people, Manale said. Members of the public should keep an eye on their banks accounts, going back as long as one or two months, he said, and if they suspect fraudulent activity, call their banking institution and local law enforcement agency.

Follow Sara Pagones on Twitter, @spagonesadvocat.