Washington: Police said a woman called from inside a Washington navy yard building, located less than 2 miles (3 kilometers) from the Capitol, to report that she might have heard sounds of gunshots early in the morning. However, investigators found no sign of a shooting, a shooter or anyone injured. No arrests have been made and no weapons were found, officials said.
"There is no evidence of any victims today,: District of Columbia mayor Muriel Bowser said.
Navy security saw surveillance video of two people jumping the fence in the vicinity of the building a couple of minutes before the report of gunfire, according to officials. Security found no one inside the building.
Officials do not believe the report was a hoax, DC police chief Cathy Lanier told reporters. Investigators interviewed the woman who made the call, Lanier said, and she did exactly as authorities regularly tell people: Report anything you think may be suspicious.
The alert triggered a large response in keeping with protocols established after the 2013 massacre. Law enforcement agents and fire fighters rushed to the scene and a helicopter hovered overhead.
In September 2013, a military contractor killed 12 civilian workers at the navy yard's Building 197 before he was fatally shot by police.
The Washington navy yard is an administrative center for the US navy and the oldest naval installation in the country.