P.F. Chang's has provided an update on the data breach it disclosed in June, revealing that the incident affected 33 restaurants with a specific timeframe for each location.

Ten of the intrusions began on October 19, 2013, with other intrusions beginning in February and April of 2014. Most intrusions lasted until June 11, 2014, with two of the earliest affected restaurants considered secure much earlier; a location in Charlotte was affected for only a week. There have been no further incidents in the past two months, the company said.

At the affected restaurants, an intruder gained access to customers' card numbers and, in some cases, their names and/or the cards' expiration dates. However, P.F. Chang's still has not identified the specific cardholder data affected.

The restaurant chain's investigation with the United States Secret Service and third-party forensics experts is ongoing, said Rick Federico, chief executive of P.F. Chang's, in an Aug. 4 press release.

"P.F. Chang's encourages its guests to remain vigilant and seek to protect against possible identity theft or other financial loss by reviewing account statements for any unusual activity, notifying their credit card companies, and monitoring their credit reports," Federico said in the release.

A company website, pfchangs.com/security, provides any updates related to this investigation. It also established a hotline to answer questions by phone.