US Senate buildings locked down over reports of ‘active shooter’

US Capitol Police officers clear a stairwell in the Dirksen Senate Office Building on Capitol Hill. Photo / AP

US authorities have issued a shelter-in-place order and started searching Senate office buildings near the US Capitol amid reports of an active shooter.

The US Capitol Police announced on the X social media platform on Wednesday afternoon (Thursday morning NZT) that the security response was prompted by a “concerning 911 call” regarding a “possible active shooter”.

However, as of 3pm, the Capitol Police noted that there were no confirmed reports of weapons or gunshots.

Inside the Russell Senate Office Building, officers evacuated the hallways and shouted at people to run outside and away from the building. Outside, tourists watched as dozens of police cars surrounded the area.

Government staffers leave the Russell Senate Office Building. Photo / AP

Staff and journalists working in the building received an email instructing them to take shelter in a locked room, remain quiet and silence all electronics.

Both the House of Representatives and the Senate are currently on recess and the office buildings are generally less crowded than usual.