P.F. Chang's announced today that the June breach of its card security system involved 33 restaurants in 18 states. Southern California locations were hit the hardest in the widespread breach, representing seven of the 33 locations compromised.

"We have identified certain P.F. Chang's China Bistro branded restaurants in the continental United States where we believe certain credit and debit cards used during specified time frames may have been compromised, and we have posted a list of those restaurant locations and time frames," said P.F. Chang's CEO Rick Federico. "We are committed to providing support and resources, including complimentary identity protection services, for all guests that may potentially be affected by the security compromise."

The Scottsdale, Ariz.-based chain announced that it had determined none of its take-out stores were part of the breach and that it believed it corrected the problem the day after the Secret Service notified it of the suspected compromise.