SOUTH BEND — At least dozens of area residents had money fraudulently withdrawn from their accounts over the weekend at locations overseas, local bank officials reported Monday.

At Teachers Credit Union, 97 members have been affected, said Paul Marsh, senior vice president for sales and marketing.

Marsh said the withdrawals — some of which have been for more than $1,000 — were all “pin-based transactions” made on debit cards at ATM machines in several countries, including Russia, Ukraine and Nigeria.

Marsh said he is not sure how the information is being obtained, but said all the withdrawals were made over the weekend.

“Right now we’re looking into how they’re doing it,” Marsh said. “We think some of them are happening when a merchant is involved at the point of sale. Somehow they’re collecting the information, and it could be a number of possibilities.” He said it was not the result of an internal breach.

Marsh is not sure if the number of people affected will increase but said reports “diminished throughout the day.” “We’re working with our members to take care of the situation,” he said.

Similar reports have been made at Notre Dame Federal Credit Union. At least 10 members there reported fraudulent withdrawals made since Saturday, said Deidre Davis, vice president of marketing and business development.

Davis said there’s been “some sort of data breach and fraudulent withdrawals” in Ukraine, Russia and Spain.

“It looks like they’re coming from debit and ATM cards, but we’re not exactly sure at this point,” she said.

“We’ve received enough calls to take a look at it,” Davis added. “We’ve blocked it so our cards cannot be used in these three countries right now. We’re taking a proactive stance so we don’t see anymore.”

At least three local people have also reported unauthorized withdrawals from their KeyBank accounts, although it is unclear if that bank has been affected by this particular fraud.

Meanwhile, Marsh said the amount of money being withdrawn from the TCU accounts varies.

In one of the police reports filed, a woman told police $106.82 had been withdrawn from her Visa debit card at a location in Novosivirsk, Russia. A local man told police $1,300 had been taken from his ATM card in the same Russian town. And another person had eight withdrawals on his card from the town, including four for $400 or more.

“Our detectives are being assigned to the cases and are working with the banks,” said Sgt. Bill Redman, a St. Joseph County police spokesman.