Security officers shot and critically injured a man Friday outside the White House in Washington after he brandished a weapon and refused repeated orders to put it down.
A Secret Service officer shot the man during the altercation at one of the White House security gates, in sight of tourists and passers-by in the heavily trafficked area.
The White House issued a security alert and briefly placed the facility on lockdown, but the midafternoon confrontation was over and the lockdown lifted within about an hour.
The man, who was identified as being from Pennsylvania and in his mid-30s, remained in critical condition at a local hospital hours later.
The Secret Service said that the man did not breach the White House grounds and that no one inside the White House complex had been harmed.
A White House official said, "No one within or associated with the White House was injured, and everyone in the White House is safe and accounted for. The president has been made aware of the situation."
President Barack Obama was away for the afternoon, playing golf at nearby Joint Base Andrews in Maryland. Vice President Joe Biden was at the White House but was reported to be safe.
Police said they found additional ammunition in a car parked near the White House grounds. Officials said they found no links between the man and organized terrorism.
It is not uncommon for people to try to breach the White House grounds without permission. Last year, the Secret Service added small spikes to the fence surrounding the property, following several incidents in which people climbed over the barrier and were apprehended by security.
The agency last month announced a plan to increase the height of the fence from 2 meters to nearly 3 (from 6½ feet to nearly 10).