Food stamp recipients in 17 states lost access to the electronic system used by stores to verify their benefits on Saturday, leaving many unable to buy groceries, the company that manages the system said.
People enrolled in the government food assistance program use plastic vouchers similar to debit cards. Starting at about 11 a.m. EDT (1500 GMT), some of those cards stopped working, Xerox spokesman Kevin Lightfoot said.
A power outage that started the problem was fixed within 20 minutes, Lightfoot said, but shoppers continued to run into difficulties throughout the day. By early evening, the problem still had not been fixed.
Edlyn Bautista, assistant manager at the Food Basics supermarket in Belleville, New Jersey, said many customers abandoned their groceries in frustration.
"A lot of carts were left behind," Bautista said. "The store is empty."
At the Pathmark grocery in Newark, New Jersey, workers had to reshelve perishable items after customers walked away, according to store officials.
"Initially the customers were leaving carriages in the aisle because we couldn't give them a timetable," said a store manager who asked not to be identified. "It's been an all-day thing."
The glitch was unrelated to the partial federal government shutdown that began on October 1, Lightfoot said, adding that it was not unclear how many beneficiaries were affected.
The breakdown involved the Supplemental Nutrition Assistance Program and the Women, Infants and Children program.
In most states, retailers can get permission to issue emergency paper vouchers that allow people to buy food. But some states limit the value of those vouchers, Lightfoot said.
For example, beneficiaries in Ohio can buy no more than $50 of groceries on an emergency voucher, he said.
States experiencing problems included Alabama, California, Georgia, Iowa, Illinois, Louisiana, Massachusetts, Maryland, Maine, Michigan, Mississippi, New Jersey, Ohio, Oklahoma, Pennsylvania, Texas and Virginia, Lightfoot said.