Three people, including a police officer, were injured after authorities say a driver tried to enter the secure campus of the National Security Agency at Fort Meade on Wednesday morning and someone opened fire.
Gunshots were fired during the incident, but officials say they do not believe any of the injuries resulted from gunfire.
The FBI is still collecting evidence but believes it was an isolated incident, Gordon Johnson, special agent in charge of the FBI's Baltimore field office, said at a news conference Wednesday afternoon.
"I cannot emphasize enough that we believe there is no indication that this has a nexus to terrorism," Johnson told reporters near the site of the incident, in Maryland, about 20 miles northeast of Washington, D.C.
Johnson said the three people injured were the driver of the vehicle, an NSA police officer and a civilian onlooker. He would not give any details about how they were injured or who opened fire.
The FBI is leading the investigation.
Two other people who were in the vehicle have been taken into custody and were being questioned, Johnson said. The injuries suffered by the police officer and the onlooker did not appear to be life-threatening, he said. He did not have any information about the driver's injuries.
The incident began when the vehicle tried to enter the spy agency's campus without authorization about 7 a.m., the NSA said in a statement. The statement said weapons were fired but "preliminary reports do not presently indicate that there are injuries attributable to gunfire."
Chopper4 footage showed a black SUV with at least two bullet holes through the windshield. The vehicle was stopped near concrete barriers, with its airbags deployed. Officers could be seen surrounding a man sitting on the ground in handcuffs.
The White House said President Donald Trump has been briefed on "the shooting at Ft. Meade."
"Our thoughts and prayers are with everyone that has been affected. We will continue to provide updates as they become available," the White House said in a statement.
After the shooting, Highway 32 was closed in both directions near the campus during rush hour, and Fort Meade urged drivers to "take alternate routes, expect long delays and drive carefully."
The NSA's presence is clearly visible in the area, with large satellite dishes and glass and steel buildings rising from the tree line. Chain link fences marked with restricted access signs and topped with barbed wire run along the perimeter of the campus. Fort Meade, a United States Army installation, is home to approximately 10,000 military personnel. More than 51,000 military, civilian and contract employees work at the installation.
Despite prominent highway signs, drivers occasionally take the wrong exit and end up at the tightly secured gates. Most motorists then carefully follow the orders of heavily armed federal officers and turn around without getting into more trouble.
But in early 2015, two people were shot at by NSA police when they disobeyed orders outside the heavily secured campus. One driver died at the scene after NSA police opened fire on a stolen sports utility vehicle. Authorities later said they had stolen a car from a man who picked them up for a party at a motel.