The shooting at the White House on Thursday was the latest in a string of shootings at the president’s home.
There were no injuries.
The incident began around 1:30 p.m. local time (0530 GMT) as a confrontation between two people and escalated, with shots fired.
Police later said the two suspects, who have not been identified, fled the scene.
The White House was not immediately accessible for comment.
The shooting comes amid heightened tension between the US and North Korea following the death of North Korean leader Kim Jong-un, who is under house arrest in a political prison near the border.
The White House said the shooting occurred as the White Helmets were preparing to fly to North Korea to attend a UN emergency meeting.
“This morning, we are in the process of preparing to deliver a White Helmet rescue team to North Korean government headquarters,” the White house said in a statement.
The group was headed to North Pyongyang on a humanitarian mission, the statement said.
A video posted to Twitter by White House correspondent Pete Williams showed a woman in an ambulance wheeling a stretcher out of the White Senate and the White Houses back rooms.
In the footage, a woman and a man are seen wheeling out of one room and the other hallway.
The ambulance then stops at the back of the room, as the two people who are seen walking in are seen holding hands.
The Associated Press contributed to this report.