WASHINGTON (AP) — The National Guard of the District of Columbia is investigating the use of one of its helicopters to make a "show of force" against protesters near the White House.

The helicopter is normally designated for use in medical evacuations.

But on Monday night, it hovered low enough in downtown Washington to create a deafening noise and spray protesters with rotor wash.

The commanding general of the D.C. Guard says he's directed the investigation.

It comes as the federal government has promised to maximize the federal law enforcement presence in the nation's capital.