BANGOR, Maine — Bangor Savings Bank warned Mainers on Friday that they are being targeted by a phone scam.

Twenty people have reported receiving automated messages on their cell phones that purport to be from Bangor Savings Bank, bank spokesman and senior vice president Yellow Light Breen said.

The messages ask customers to provide their credit and debit card account numbers, PINs or security codes in order to avoid deactivating the cards. That’s a bad idea, Breen said.

“The best way to protect yourself is also the simplest,” Breen said. “Don’t give out your information. Period.”

Customers and noncustomers have received the automated voice mail message, which is a type of phone scam known as “vishing.” It is becoming increasingly common, Breen said.

He emphasized that that there is “absolutely no evidence” the perpetrators have any information about bank customers. Breen said he thinks that it is an automated dialing program focusing on cell phone users from the Bangor area and Down East.

“We would never call you asking about your account number because we already have that,” Breen said. “An outbound telemarketing call would never be from your real bank.”

Only three Bangor Savings Bank customers reported that they had given out the requested information, and those customers have been issued new cards.

Breen said that if customers who fell for the scam promptly notify bank officials, they won’t be liable for any fraudulent charges made on their accounts.

“We’re investigating and gathering information,” Breen said. “Because we didn’t know the scope of the scam, we wanted to get out there and educate our customers about it.”