The U.S. State Department said Tuesday that it is investigating "anomalies" in its unclassified computer system, according to reports by major wire services.

The State Department found significant break-ins of computers used to work on international relations with China and North Korea, according to a report by the Associated Press.

Nancy Beck, department spokeswoman, told the Washington Post today that the problem was not a virus, and that an investigation was ongoing.

News reports on Tuesday said that investigators, speaking on the condition of anonymity, thought hackers stole sensitive information and passwords and implemented backdoor trojans on the department's PCs.

The federal government's information security practices have suffered a number of black eyes in recent weeks beginning with the theft of a Department of Veterans Affairs laptop that resulted in the compromise of more than 26.5 million veterans and active duty members of the Armed Forces.

The laptop was later recovered, and investigators determined that the personal information had not been misused.

In the following weeks, other federal departments such as the FTC and Department of Agriculture – as well as the U.S. Navy and Marine Corps – suffered personal information breaches as well.