By DEVLIN BARRETT, Associated Press Writer - Thu May 21, 2009

WASHINGTON - Law enforcement computers were struck by a mystery computer virus Thursday, forcing the FBI and the U.S. Marshals to shut down part of their networks as a precaution.

The U.S. Marshals confirmed it disconnected from the Justice Department's computers as a protective measure after being hit by the virus; an FBI official said only that that agency was experiencing similar issues and was working on the problem.

"We too are evaluating a network issue on our external, unclassified network that's affecting several government agencies," said FBI spokesman Mike Kortan. He did not elaborate or identify the other agencies.

Marshals spokeswoman Nikki Credic said the agency's computer problem began Thursday morning. The FBI began experiencing similar problems earlier.

"At no time was data compromised," said Credic. The type of virus and its origin were not determined.

Spotted here