A gunman opened fire near the White House on Saturday evening, with U.S. Secret Service agents killing the assailant in a shoot-out during which a bystander was also struck, authorities said.

Correspondents stationed near the White House said they heard what appeared to be repeated gunfire on Saturday, triggering an immediate security response around the grounds.

CNN reporters heard what appeared to be dozens of gunshots near the White House, triggering a lockdown and a rapid response from the US Secret Service.