The Pentagon on Tuesday imposed the emergency shutdown of a classified internal communications network, three Defense Department sources told Just the News.

The unprecedented daytime shutdown occurs in the wake of recent reports that hackers violated several government departments, including the Department of Homeland Security.

The Defense Department alerted staff that for emergency software updates, the SIPRNET system was being shut down in the late morning.

A request for comment, including one on whether the shutdown was linked to the hacking allegedly reported on Sunday by Russian agents, was not immediately returned by the Pentagon.

The system known as the Secret Internet Protocol Router Network, handles, up to the secret level, classified information and has been shut down for several hours.

“This has never happened in the middle of a work day,” one Pentagon official said. “Updates usually are done on weekends and after hours late at night. This was done on an emergency basis.”

The shutdown only applied to computers handling classified materials and was not imposed on other computers or telephone systems.

“Pentagon goes dark. Keep in mind that the president controls the military and Trump is still prez. Looks like the CIA is out of the loop,” one tweet reacted to the news.

“This is pretty serious. DoD has shutdown the SIPRnet,” another commented.

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