UPDATE (9:42 AM EST): The U.S. Capitol has been lifted. No further details have yet been released as to why the lockdown was implemented.
UPDATE (9:34 AM EST): The Washington Examiner reports that the Capitol building was placed on lockdown following reports that a woman had entered a House office building with a gun. MRCTV will bring you more details as they arrive.
UPDATE (9:26 AM EST): CNBC is reporting that police are looking for an individual, but that authorities provided no further details.
ORIGINAL STORY: Capitol Hill has been placed on lockdown, according to an email sent from the House TV and Radio Gallery at 9:08 a.m.
The advisory notice asked that building occupants close and lock all doors, stay away from windows and silence all phones. All House and Senate business has been suspended until further notice.
This story will be updated as more information becomes available.