Police closed a stretch of Constitution Avenue near the White House Friday night to investigate reports of gunfire in the area and recovered an AK-47 assault rifle.

Sgt. David Schlosser of the U.S. Park Police said the White House did not appear to have been the focus of the incident.

Secret Service spokesman Edwin Donovan said witnesses heard shots and saw two vehicles racing on Constitution Avenue toward 17th Street, and one of the vehicles was abandoned at 23rd and Constitution.

Witnesses saw the driver get out and run across the Roosevelt Bridge toward Arlington, Virginia, Donovan said. He said an AK-47 assault rifle was recovered but no one is in custody.

Police were looking for bullet holes and had not confirmed that shots were actually fired.