U.S. State Department shuts down e-mail system after hackers attack its computers

Computers at the U.S. State Department have reportedly been hacked, and its technicians have taken the unprecedented step of shutting down the entire unclassified e-mail system to repair possible damage caused by the hacker attack.

Media reports quoted officials of the department, as saying on Sunday that an "activity of concern" was detected in the system around the same time as a previously reported incident that targeted the White House computer network in October.

The State Department said it shut down the e-mail system late on Friday as part of a scheduled outage of some of its internet-linked systems to make security improvements to its main unclassified computer network.

The official was not authorized to speak about the matter by name and

spoke on condition of anonymity.