Luxury retailer Neiman Marcus says thieves stole some of its customers’ payment card information and made unauthorized charges over the holiday season.

Neiman Marcus’s spokeswoman Ginger Reeder said in an email that its credit card processor notified the retailer in mid-December about potentially unauthorized payment card activity. On Jan. 1, a forensics firm confirmed evidence that the upscale retailer was a victim of a criminal cyber-security intrusion and that some customers’ cards were possibly compromised as a result.

Reeder says the Dallas-based retailer is working with the Secret Service.

Reeder wouldn’t estimate how many customers may be affected.

It’s the second cyber attack on a national retailer in recent weeks. Target disclosed Friday that its massive data theft before X-Mas was significantly more extensive than previously believed.

(AP)