The shots damaged the outside of a south wall of the Pentagon, with shell fragments embedded in two windows, Mr. Layman said. The impact shattered the windows.
Investigators were trying to determine whether there was a connection between the Pentagon shooting and an incident in which shots were fired at the National Museum of the Marine Corps over the weekend.
Steven Calvery, the director of the agency, said at a news conference that officials considered the Pentagon shooting a random event.
The agency closed all access to the building for nearly an hour and conducted sweeps of the area with Arlington County police officers, though nothing related to the shooting was found, Mr. Layman said. Interstate 395 was also temporarily closed.
For safety measures, we didn't want anyone leaving or coming into the building, Mr. Layman said.
He said investigators were still trying to determine what type of gun was used in the shooting.
Bullet holes were discovered Monday in a wall of the Marine Corps museum in Triangle, Va. According to a police spokesman in Prince William County, where the museum is located, the shots were fired late at night on Sunday, when no one was inside. Several bullet holes could be seen in the glass, and damage was estimated at $20,000.
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In an apparently
unrelated incident
shots were also
fired at