LOS ANGELES (CBSLA/AP) — Whole Foods said Friday the credit and debit card information of customers who bought meals or drinks at its in-store restaurants or bars have been exposed to hackers.

The grocer, which was recently acquired by Seattle-based online retailer Amazon.com Inc., says the data breach did not affect its main checkout registers or any Amazon.com shoppers.

READ MORE: Newsom Announces Plans To Expand Stretch Of Interstate 15 By Next Summer

Whole Foods did not say which of its 470 stores were affected, and a spokeswoman declined to answer any questions. The Whole Food stores that do have in-store restaurants and bars tend to be in or near cities.

Whole Foods says it is investigating the hack.

READ MORE: Bob Dole, Who Overcame Severe WWII Wounds To Lead Senate GOP And Run For President, Dies At 98

It’s the latest incident at an eatery in two days. On Tuesday, Sonic reported “unusual activity” on credit cards used at some of its restaurants.

In a statement, the fast food chain said its credit card processor notified them of the incident last week and that it’s now “working to understand the nature and scope of the issue.” Sonic did not disclose how many credit cards were potentially involved in the incident or when the incident took place.

Sonic has more than 3,500 restaurants in 44 states. News of the possible breach sent Sonic Corp.’s stock plummeting Wednesday.

MORE NEWS: 16-Year-Old Arrested In Connection With Burglary Of Business In Santa Paula

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)