Police officers shut down the area around the Environmental Protection Agency's headquarters Wednesday after a report of gunshots being fired in the building that was later determined to be unfounded.

Photos from the area near Pennsylvania Avenue NW and 12th Street NW showed police vehicles parked all around the building blocking off the area, and videos showed police sprinting around the building.

An EPA spokeswoman confirmed police were there after reports of shots fired.

"The Federal Protective Service and DC Police responded to reported gunshots at EPA HQ. No injuries, building is now secure," tweeted Liz Bowman, public affairs officer for the EPA.

An officer with the Department of Homeland Security told the Washington Examiner the report of gunshots was "unfounded" and a "mistake."

Just before 6 p.m., Bowman said police had completed their investigation.

"The floors where the shots were reported were cleared. FPS says that the gunshot reports were unfounded, there were no injuries and the building is secure," she said in a statement to the Washington Examiner.

A source with knowledge of the situation said employees were clear to return to the building as of 5:30 p.m. Wednesday.

During the incident, the EPA told its employees police were responded to reports of gunshots.

The EPA told employees in a message there was a report of at least one shot was fired, but they could not confirm that information.

"Police are on-site in the WJC (William Jefferson Clinton) North Building responding to a reported gun being fired in the North Building," the message obtained by the Washington Examiner stated.

"We have no confirmation that anything has occurred at this time, however, the investigation is underway. We will keep you informed as we learn additional information. In the meantime, please follow any direction you receive from police on your floor."