SANTA ROSA, Calif. — Redwood CU has cancelled 18,400 debit cards in the face of an apparent hacking into the database of Raley's supermarket chain that has led to fraud on as many as 200 of its member accounts.

One member reported yesterday morning that someone had withdrawn $500 from his Redwood account at a Las Vegas ATM.

Another member said the credit union alerted her that someone tried to use her card number to charge a $224 purchase at a Walgreens in Ohio.

Raley's, which operates 115 supermarkets in California and 13 in Nevada, has yet to acknowledge a breach though the company confirmed it has heard from customers via Facebook, email and its toll-free customer service phone number reporting fraudulent charges made out of state.

The company issued an alert to customers saying it recently discovered that a portion of its computer network systems may have been the target of a complex, criminal cyber attack. "Our customers' peace of mind is our top priority. We take protecting our customers' privacy seriously and sincerely regret any inconvenience that the attack on our network may have caused," said Mike Teel, president of Raley's. "We are working around-the-clock to gather details to determine the extent of any possible compromise of customer information."

Other credit unions have been hit as well. One member of SchoolsFirst FCU reported a $95 charge was made on her card in Atlanta and a second charge, for $125, was stopped by the credit union before it went through.

Dow Great Western CU also reported several incidents and blocked all merchant Point of Sale  transactions that do not require a PIN. Dow told members the fraudulent transactions it has seen indicate that the card information obtained from the Raley's breach allowed the cards to be cloned. The cards are being used at retail merchants all over the nation. Criminals are using the cloned cards by selecting "credit" and then signing for the transaction, thus avoiding the use of a PIN.

Members 1st CU notified its members it blocked transactions from India, the country identified as the origin of some fraudulent charges. Delta Schools CU is reissuing debit cards to all of its members who have shopped at a Raley's, as a precaution.