WASHINGTON (CNN) -- Capitol Police said Friday they were investigating reports of sounds of gunfire in the garage of the Rayburn Office Building, where members of the House have their offices.
The entire Capitol complex has been locked down, CNN's Dana Bash reported.
"Capitol police are investigating sounds of gunfire in the Rayburn garage," CNN producer Deirdre Walsh reported from the Rayburn Building.
Tunnels connect all of the buildings in the complex.
"They have no victims at this time, and they have no active shooter," said Mike Brooks, a law enforcement expert.
He noted that Capitol Police have a firing range in the basement.
The Containment and Emergency Response Team was searching the area, Brooks said.
Tunnels connect all of the buildings in the complex.
The alert came moments after a press conference held by Rep. John Sensenbrenner on immigration reform, Walsh said.
"We saw several Capitol Hill police officers running quickly down the hallway," she said. Soon after that an announcement was made throughout the building.
Rep. Peter Hoekstra, R-Michigan, was conducting a House Intelligence Committee hearing at the time, according to an Associated Press report. Hoekstra interrupted a witness to tell those at the hearing to remain in the room and said doors must be 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 told AP.
Business continued as usual on the Senate side, Bash said.
