http://news.bbc.co.uk/2/hi/americas/5021114.stm
Police in Washington DC say they are investigating after the sound of gunfire was heard in a House of Representatives office building.
The US Capitol has been sealed off and people in the building have been told not to move.
The apparent shots were heard at the garage level of the Rayburn building, which houses offices of members of the US House of Representatives.
No casualties have been reported, and police are searching the area.
The House of Representatives is not in session, but a committee hearing was going on at the time of the incident.
Representative Peter Hoekstra, conducting the hearing, told Associated Press he interrupted a witness to request those attending to remain in the room and ordered the doors closed.
"It's a little unsettling to get a Blackberry message put in front of you that says there's gunfire in the building," he said