GOLDEN VALLEY, Minn. -- Golden Valley Police say in the past month they've investigated eleven cases of credit/debit card fraud.

The suburban Twin Cities police department gets several fraud cases every week, said Sgt. Randy Mahlen. But the way the fraud is committed is always changing.

"Typically the card number is purchased--often times on the internet," said Mahlen. "On the dark web people can purchase credit card information, then they make counterfeit cards which are then used either online or in retail stores."

Mahlen says one case police are investigating now involves large fraudulent purchases from a Golden Valley restaurant. He says the suspect is likely an employee and the victims are the restaurant's customers.

"If you give your credit card to a server, they can bring it in the back and swipe the card, pulling the data from it," said Mahlen.

Mahlen says another case his department recently handled involved a Golden Valley woman who's credit card information was compromised by someone out of state. He says the criminal used the woman's card to purchase American Airlines tickets out of Detroit.

As for credit card skimming cases, Mahlen says they're less common ever since chip cards came onto the scene. Malen says Golden Valley Police haven't recovered a skimmer in over a year.

"We haven't seen technology that's able to replicate that chip within the credit card, so I think that's why we're seeing a decrease in the skimmer cases," said Mahlen.

Golden Valley Police offered the following tips from the FTC to help people avoid credit and debit card fraud:

• Don’t give your account number to anyone on the phone unless you’ve made the call to a company you know to be reputable. If you’ve never done business with them before, do an online search first for reviews or complaints.
• Carry your cards separately from your wallet. It can minimize your losses if someone steals your wallet or purse. And carry only the card you need for that outing.
• During a transaction, keep your eye on your card. Make sure you get it back before you walk away.
• Never sign a blank receipt. Draw a line through any blank spaces above the total.
• Save your receipts to compare with your statement.
• Open your bills promptly — or check them online often — and reconcile them with the purchases you’ve made.
• Report any questionable charges to the card issuer.
• Notify your card issuer if your address changes or if you will be traveling.
• Don’t write your account number on the outside of an envelope.