Police in Washington, D.C say they are investigating reports of the sound of gunfire at a Congressional office building on Capitol Hill.

The sound of shots was reported in a garage beneath the Rayburn building, which holds offices of members of the House of Representatives.

There have been no reports of injuries or any gunman.

The Rayburn building is part of the multi-building Capitol Hill complex, which houses both the Senate and the House. Police briefly placed much of the complex under lockdown, but they now appear to be concentrating solely on the Rayburn building.