(CBS) - P.F. Chang's is confirming that data from credit and debit cards used at its restaurants was stolen.
The company says it learned about the security breach on Tuesday from the U.S. Secret Service and began investigating the breach with the agency and a team of forensics experts. It found that credit card and debit cards were exposed, but it doesn't know yet when it started happening and which stores were affected.
The company didn't say how many cards were affected.
It is now using manual credit card imprinting devices at all its P.F. Chang's restaurants to process card payments while the investigation continues.
"Because we are still in the preliminary stages of our investigation, we encourage our guests to be vigilant about checking their credit card and bank statements," CEO Rick Federico said in a statement.
The company has set up a website to provide updates about the breach.
Scottsdale, Arizona-based P.F. Chang's China Bistro Inc. owns its namesake restaurants and Pei Wei Asian Diners. There are 209 P.F. Chang's restaurants around the country.