Authorities are warning Nebraskans about a scam involving classified ads.

The Nebraska State Patrol says that the scammer will call someone who placed a classified ad and tell that person that the credit card payment used to place the ad didn't go through.

The scammer asks for the card number again. Then the scammer calls back later to say the payment still didn't go through and asks for another credit card number.

The scammer then could have two credit cards to make charges on until the cardholder or a card company catches on to the scam.

State Patrol Capt. Chuck Phillips says people should ask for verification of payment when using a credit card for an ad.