A card skimmer was discovered at a Bank of America ATM in downtown San Luis Obispo on Sunday.

An employee of the bank, located at the corner of Higuera and Santa Rosa streets, was checking the ATMs Sunday morning when the skimmer was found, according to a San Luis Obispo Police Department Instagram post.

At least one fraud report has already been filed in relation to the skimming device, the post said.

“Skimmer technology is evolving. Skimmers were externally mounted on card readers and the internally placed versions are out there,” the release said. “Please stay vigilant: Report fraudulent charges as soon as possible if you are a victim of skimming.”

The Bank of America location where the skimmer was located is at 1102 Higuera St. in San Luis Obispo.