Security officials did not provide details of the incident and it was unclear whether shots had been fired by a suspect or by law enforcement. "The situation is under control and there is no ongoing security of safety threat".
The National Security Agency/Central Security Service is one of the US government's main spy agencies.
This is a breaking news story.
After FBI report on agent's death, Cornyn warns against jumping to conclusions
President Trump tweeted about the death, writing, "Border Patrol Officer killed at Southern Border, another badly hurt". But the F.B.I. report makes clear that the authorities knew very little in the moments after the episode.
An NSA spokesman told local media the area outside America's electronic espionage agency was now secure after a "security incident".
The FBI's Baltimore office said it had sent agents to the scene and that the incident had been contained.
Photos emerged on social media appearing to show a black van at the building's entrance and a handcuffed man, possibly an attacker, sitting on the ground. WRC said bullet holes could be seen in the vehicle's front window, and several air bags were deployed.
US President Donald Trump has been "briefed on the shooting", AP reports, citing White House spokeswoman Lindsay Walters.
'True American heroes': Two Ohio officers killed responding to hung-up 911 call
The Fraternal Order of Police of OH asks anyone who wishes to support the families to donate at GoFundMe.com/FOPLodge9HelpFund. I have spoken with Westerville city leaders and pledged the full assistance of the Ohio Highway Patrol in any way they need.
The local Anne Arundel County police forces shared an information about a possible shooting around 7:30 a.m. local time.
The police are investigating the incident.
In March of 2015, one person was killed and another was wounded when they drove a stolen SUV up to the NSA gates and refused orders to turn around. Authorities later said they had stolen a auto from a man who picked them up for a party at a motel.
Israel downs Iranian drone, Syria hits Israeli jet
The Israeli military said it did not seek escalation, calling its action a defensive response to an Iranian act of aggression. The confrontation was the most serious between arch foes Israel and Iran since the start of the civil war in Syria in 2011.