A gunman was shot dead by United States Secret Service agents on Saturday evening after opening fire near the White House security perimeter in Washington, DC, triggering panic around the presidential complex and forcing journalists and tourists to flee for safety.

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.