The U.S. Secret Service said a man carrying a gun opened fire on plainclothes officers near the White House on Monday and was killed in an exchange of gunfire with law enforcement near the Washington Monument, prompting a large police presence and a brief lockdown near the White House area. Secret Service Deputy Director Matt Quinn told reporters that plainclothes agents spotted the man around 3:30 p.m. and saw an imprint of the weapon on him before the agents contacted uniformed officers.

Quinn said the man tried to flee when uniformed Secret Service approached, and that he fired at officers. He said the officers returned fire and the suspect was transported to a local hospital. Quinn said he did not have information on the suspect’s condition.

Quinn added that emergency personnel also transported a minor who had been shot but was not seriously injured. He said he could not say definitively that the bystander was struck by shots from the suspect’s gun, but he said investigators believe the minor was hit. Washington, D.C., police would investigate the officer-involved shooting, Quinn said.

As crews responded near the White House, the Secret Service encouraged people to avoid the area. The White House was briefly locked down during the investigation, and the Secret Service ushered journalists who were outside into the briefing room, according to Quinn.

The Secret Service said President Donald Trump was holding a small business event and continued without interruption. The incident came just over a week after a gunman tried to storm the White House Correspondents’ Association dinner with guns and knives, an event in which a Secret Service officer was shot.

Quinn said it was not known yet whether Monday’s incident was related to Trump. “Whether or not it was directed to the president or not, I don’t know, but we will find out,” he said, adding that investigators would determine what, if any, connection existed.

The case is being investigated as an officer-involved shooting by Washington, D.C., police, the Secret Service said.