The State Department is warning nearly 400 passport applicants of a security breach in its records system that may have left them open to identity theft.

Most of those applicants live in the Washington, D.C. area. A spokesman says their passport applications containing personal information, including Social Security numbers, may have been illegally accessed back in March and used to open fraudulent credit card accounts.

So far, most of the 383 people contacted have not been victimized by identity thieves. All can get free credit monitoring for a year.

The State Department has been working with D.C. police investigating a credit card and identity theft ring, which was exposed after the arrest of a man found with 19 credit cards in different names and eight completed passport applications.