Attorney General William P. Barr personally ordered law enforcement officials on the ground to extend the perimeter around Lafayette Square in Washington, D.C. to push back protesters just before President Trump spoke Monday, a Justice Department official said.

That order came as clashes between police and the public continued to intensify, with largely peaceful daytime protests over George Floyd’s death in Minneapolis police custody descending into violence and chaos after dark, amid widespread curfews and National Guard deployments.

As the mayhem spread and police escalated their use of force⁠ — firing gas and rubber bullets at peaceful protesters in cities from Washington, D.C., to Walnut Creek, Calif. — authorities across the United States also said they were under assault, with officers shot in St. Louis and Las Vegas and others struck and injured by cars in New York as authorities looked to contain unrest.