The NSA said the situation was under control.
It's unclear what led to the shooting, but photos of the scene show a black SUV with bullet holes in its windshield.
The Army installation's fire and emergency services reported transporting an injured person to a hospital, Fort Meade public affairs officer Chad Jones told ABC News.
It said: "The President has been briefed on the shooting at Ft".
"Our thoughts and prayers are with everyone that has been affected", Walters said.
The Anne Arundel Police Department is not the investigating agency, the department said on Twitter.
'We will continue to provide updates as they become available, ' the White House said in a statement.
NSA police, the Federal Bureau of Investigation and local law enforcement responded to the shooting, sources told CBS News.More news: Ice hockey - Slovenia down United States 3-2 in overtime
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A handcuffed man was on the ground, surrounded by police, NBC Washington said.
Authorities asked drivers to avoid the area.
Meade officials confirmed that the incident happened on the Canine Road gate to the NSA.
In 2015, two men dressed as women tried to ram a stolen vehicle through the gate of the NSA headquarters at Fort Meade.
That incident was not believed to be linked to terrorism or a planned attack.
The NSA released a statement saying "NSA, police and law enforcement are addressing an incident this morning at one of NSA's secure vehicle entries".
Authors Information: Dana Hedgpeth is a Washington Post reporter, working in the early morning to report on traffic, crime and other local issues.