PHOENIX – Arizona authorities uncovered 30 additional skimming devices at gasoline stations across the state last week, bringing the 2016 total to 78, ABC15 reports. The Arizona Department of Agriculture has been investigating skimming, which is up sharply from 2015 when only 11 devices were discovered in gas pumps.

This year, the majority of the devices, which capture a customer’s credit or debit card number, have been in the Tucson and Phoenix metro areas. The state is partnering with federal and local officials to uncover the perpetrators.

“We have criminal gangs coming into Arizona who are implanting into our gas pumps skimmers that steal credit card numbers,” said Mike Killian, director of the Arizona Department of Agriculture, in an August news report on skimming.

Gasoline retailers have been upping security at stations to combat skimming. At Sam’s Club, spokeswoman Delia Garcia said the company regularly checks security seals on all pumps. “There’s also video surveillance that monitors all our gas station bays, and even if someone were able to breach this mechanism they’re not going to be able to actually breach the actual equipment to attach skimmers to it,” she said. “If they did, our pumps would be inoperable.”

Earlier this month, a Georgia gas station attendant foiled an attempt to install a skimmer. Wisconsin officials has also reported an uptick in skimming devices at gas stations recently.

Read “Secure Your Pump” from the May NACS Magazine for more on combating skimming. And visit the NACS Skimming and Payments Security webpage for resources on how to prevent and mitigate skimming attacks.