WASHINGTON D.C. (CBS News) — Fans were asked to leave Nationals Park after a shooting that occurred outside the stadium led to a panicked scene with attendees ducking for cover and the teams retreating to their clubhouses.

Metro Police initially said two people had been shot and later added that “two additional victims associated with this incident” were being treated for gunshot wounds at local hospitals.

The shooting occurred prior to start of the bottom of the sixth inning “outside of the Third Base Gate,” according to the Washington Nationals. CBS News congressional correspondent Kris Van Cleave, who was in attendance at the game, reports that the sound of gunshots could be heard inside the stadium and many in the stadium began running for cover.

CONTINUE AT CBS NEWS: Nationals game suspended as fans rush for exits after shooting outside stadium