NEW YORK (AP) — Target is getting hit with another lump of coal this holiday season. The nation's second-largest discount retailer said Tuesday that an unidentified number of gift cards sold over the holidays were not properly activated.

The Minneapolis chain says the number of cards affected was less than 0.1 percent of the total sold and that it will honor the affected cards.

Holders of Target gift cards can check the balance by following instructions on the back of the card. Customers can bring faulty cards to any Target service desk or call 800-544-2943 for help.

"We are aware that some Target gift cards were not fully activated and apologize for the inconvenience," company spokeswoman Molly Snyder said in a statement emailed to The Associated Press.

The problem comes less than two weeks after Target announced it was hit with a massive data security breach that affected about 40 million debit and credit card holders who shopped at its stores between Nov. 27 and Dec. 15.

"It's another black eye that makes you question the internal operating procedures of Target," said Brian Sozzi, CEO and chief equities strategist at Belus Capital Advisors. "Target needs to be doing everything perfectly. It can't afford to lose any more confidence among its guests."

On Friday, Target backtracked and said that debit-card PINs were among the financial information stolen from millions of customers who shopped at the retailer in late November and early December. However, it said the stolen personal identification numbers, which customers type into keypads to make secure transactions, were encrypted and that this strongly reduces risk to customers.

In addition to the encrypted PINs, customer names, credit and debit card numbers, card expiration dates and the embedded code on the magnetic strip on back of the cards were stolen.

Target has said it is still in the early stages of investigating the breach. It has been working with the Secret Service and the Department of Justice.

Target's stock price rose 95 cents to $63.42 in afternoon trading Tuesday. It is nearly even with its price before the company disclosed the data breach.