Businesses in downtown Portland, Oregon, have lost $23 million since violent protests have wracked the city, authorities say.

Portland Police Bureau Deputy Chief Chris Davis told reporters that the intensity of the violence and length of the demonstrations have been unprecedented in the city’s history.

“It is really unprecedented in Portland’s history. We are now in our sixth week of these events, and we’re always hopeful that we’re winding down,” said  Davis. “We’ve never seen this intensity of violent, focused criminal activity over this long of a period of time.”

Protests have occurred for 41 consecutive nights following the death of George Floyd, a black man who died while a cop kneeled on his neck for eight minutes in Minneapolis, and the protesters are directing their efforts towards destroying federal property.

A group of protesters in Portland have smashed windows and set the Justice Center, a federal building, on fire, KATU reported.

Authorities have run into riots several times and have used tear gas to disperse the violent protesters.

“Quite frankly, this is not sustainable. Violence and damage have displaced the message about systemic change in the wake of the George Floyd murder,” Davis said.

On Tuesday, Oregon’s U.S. attorney announced federal charges against several protesters accused of vandalizing a federal courthouse and assaulting federal officers.

Police have also arrested two people for allegedly setting fire to a North Portland police precinct a week ago. Those two who were arrested were charged with state-level offenses.