Police evacuate part of US Senate building near Capitol

US Capitol Police are evacuating the third floor of the US Senate's Dirksen office building near the Capitol but gave no reason for the move, according to a Reuters witness.
The Dirksen Building is part of the complex surrounding the Capitol and houses various offices for US senators and their staff as well as hearing rooms.
US Capitol Police had no information on the evacuation, which interrupted a Senate hearing on the Transportation Security Administration.