A thief has stolen computer records containing identifying information on current and former employees of the state Department of Human Resources, including names, Social Security numbers, birth dates and home contact information, officials said Thursday.

DHR officials say the theft occurred about March 19. An external hard drive that stored a database was removed "by an unauthorized person," according to a statement issued by the agency.

The statement did not say how many employees are affected, but the agency employs about 19,000 people. DHR officials didn't respond to a request for information on the number of employees involved.

The agency sent letters to all employees affected by the security breach, urging them to review all credit and other financial records.

DHR officials said there is no evidence the information is being used fraudulently, and the theft remains under investigation.

The incident alarmed employees and former employees.

"On the personal side, I'm concerned that they had this kind of breach," said Jed Nitzberg, a former DHR spokesman.

He added, "I've already been in touch with one company about buying fraud monitoring and information protection services as an extra precaution because of this. I'm worried this could come back to cause real damage months from now."

Gov. Sonny Perdue said through a spokesman that the theft heightens concerns about computer security in state government.

"The governor is not happy about where the government is on this," said spokesman Bert Brantley.

Last year, the state lost personal information on 2.9 million enrollees in Medicaid and PeachCare for Kids programs.

After the recent theft, Perdue signed an executive order calling for a single set of information security reporting standards for all state agencies.

"This action will go a long way toward addressing our security gaps," Perdue said.

In the meantime, DHR is requiring employees to have password protection on jump and flash drives and portable computers that contain personnel information.

The agency also instructed workers to secure these items when away from their desks.