Secret Service guards shot a person, who was apparently armed, outside the White House on Monday, President Donald Trump said after being moved to safety in the middle of a press briefing.
Mr Trump was abruptly ushered out of the event and black-clad secret service agents with automatic rifles rushed across the lawn north of the White House.
Minutes later, he reappeared at the briefing, where journalists had been locked in, and announced that someone had been shot outside the White House grounds.
The Secret Service tweeted that it could "confirm there has been an officer-involved shooting at 17th Street and Pennsylvania Avenue".
"Law enforcement shot someone, it seems to be, the suspect. And the suspect is on the way to the hospital," Mr Trump said.
He said he knew nothing about the identity or motives of the person shot, but when asked if they were armed, he said: "From what I understand, the answer is yes."
"It might not have had anything to do with me," Mr Trump said.
He said the incident took place "on the outside" of the White House perimeter.
"I don't believe anything was breached. They were relatively far away," Mr Trump said.
Outside the White House the situation was calm, but some of the surrounding streets had been blocked off.
Police and other official vehicles converged towards the corner of 17th Street and Pennsylvania Avenue.
Philipos Melaku, a protester who has been camping in front of the White House for years, said he had heard a shot fired about 5.50pm local time.
"I heard a gunshot and before that I heard screaming," Mr Melaku said.
"It was a male voice. After that immediately, pointing their AR-15s, at least eight or nine men came in running."
After the security scare, Mr Trump returned almost immediately to the White House podium where he resumed his scheduled briefing.
Asked if he was rattled by the incident, he replied: "The world's always been a dangerous place. It's not something that's unique."
Mr Trump praised the Secret Service as "fantastic people, the best of the best".
"I feel very safe with Secret Service," he said. "A lot of terrific-looking people ready to go if something was necessary."
