Three people were arrested and several hurt Wednesday when a car crashed through the entrance of the National Security Agency outside Washington, but the incident had no link to terror, the FBI said.
The vehicle's driver, an NSA policeman and a bystander were hurt as gunfire erupted when the black SUV plowed through the gate and into concrete barriers at the main NSA entrance in Fort Meade, Maryland.
Video footage from the site showed multiple gunshot holes in the windshield of the SUV, and apparent blood on the ground outside the NSA, the premier US electronic spying agency.
"There is no indication that this has a nexus to terrorism," FBI Special Agent in Charge Gordon Johnson told reporters.
"We believe that this was an isolated incident," he said.
The three men who had been in the vehicle were all in custody, with the driver sent to the hospital with unspecified injuries. Johnson gave no information on his condition, but said none of the injuries were believed to be gunshot wounds.
The NSA policeman and the bystander were also sent to hospital, with their injuries described as "not life-threatening."
Highly secure 'Puzzle Palace'
The incident raised alarms, given that it took place at the National Security Agency, the premier US signals intelligence agency, which eavesdrops on the electronic communications and hacks the computers of US adversaries worldwide.
It also protects US communications and information systems from cyber attack
Its highly secure compound, known as the "Puzzle Palace," is located about 20 miles (32 kilometers) northeast of Washington.
President Donald Trump was briefed on the situation shortly after the shooting took place, the White House said in a statement.
"Our thoughts and prayers are with everyone that has been affected," the statement said.
Johnson would not give any details of what happened, saying the incident remains under investigation.
The SUV, believed to be rented, drove through the NSA gate at about 7:00 am (1200 GMT), and NSA security officials followed official protocols for handling such an incident, he said.
The Baltimore affiliate of CBS reported that the car was being followed by Maryland police and they took a wrong turn into the NSA entrance road, but Johnson would not confirm that report.
In March 2015, guards at the NSA gate opened fire on an SUV which did not heed orders to stop, killing the driver and wounding a passenger.
The two involved, it turned out, were men dressed as women who made a wrong turn into a restricted lane and may have refused to stop because, it later turned out, there were drugs in their vehicle.
In 1993, a Pakistan-born man wielding an assault rifle opened fire on cars waiting to enter the Central Intelligence Agency's headquarters compound in McLean, Virginia, killing two CIA employees and wounding three.
In 2016, a man drove his car into a fence gate at the CIA headquarters, claiming he was an agency recruit. He was arrested but was found to be mentally unstable, and only received 30 days in jail and a fine.