Shelter in place order issued after unconfirmed reports of active shooter at U.S. Senate office building

Reports say the U.S. Capitol Police have locked down and evacuated the Russell Senate Office Building after reports of an active shooter Wednesday afternoon.

The reports have not yet been confirmed and police are still investigating, NBC News reported.

"Our officers are searching in and around the Senate Office Buildings in response to a concerning 911 call. Please stay away from the area as we are still investigating. We will continue to communicate with the public here," read a tweet from the Capitol Police's official Twitter account.

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In a subsequent post, Capitol Police said, “If you are inside the Senate Buildings, everyone inside should be sheltering in place as the report was for a possible active shooter. It should be noted that we do not have any confirmed reports of gunshots."

This is a developing story.