After a day of protests and increasing tension across the Twin Cities, Gov. Tim Walz used a widely televised evening news conference to implore everyone to stay home and help restore order to the state's two major urban centers.

"Minnesotans, you must stay at home tonight," Walz said in hopes the curfew would serve its purpose as it remains in effect until 6 a.m. Sunday. "Don't go out, don't go walking, don't drive. … Support our first responders tonight by giving them the space to protect us."

The warning came less than eight hours after Walz ordered a full mobilization of the Minnesota National Guard to combat what he called a "tightly controlled" group of outside agitators, some of them from out of state, who have turned city streets into scenes of looting and arson.

The struggle to control the mayhem could bring another 1,000 National Guard soldiers into the Twin Cities, supplementing a force of 700, already the largest civil policing authority in the state's history. Law enforcement officials said it would be the first full mobilization of the Guard in Minnesota since World War II.

'Destabilize civil society'

"Our cities of Minneapolis and St. Paul are under assault," Walz said, suggesting that a growing number of rioters are part of what he called "an organized attempt to destabilize civil society."

Walz said many people causing destruction and fire in the cities could be from elsewhere. He distinguished the wanton looting and vandalism from the legitimate and mostly peaceful protests that began Tuesday, the day after the death of George Floyd, an unarmed black man who died after being forcibly restrained by Minneapolis police.

It was not clear if the outside groups suspected to be playing a part in the mayhem are made up of white-supremacist agitators, left-wing anarchists, or both.

Authorities said they made about 40 arrests overnight in Minneapolis and St. Paul, mostly for burglary, curfew violations and destruction of property. Hennepin County jail logs showed detainees from Florida, Michigan, Missouri, Illinois and Alaska.

Walz said that while the agitators have gotten the attention they want, he vowed that by Saturday night "they are going to get an overwhelming force of safety, security and peace."

Walz ordered another temporary curfew starting at 8 p.m. Saturday and said peaceful protesters and others who remained outside after that would be "aiding and abetting" vandals who use the crowds as cover.

Walz's announcement came after a third night of violent protests and looting, despite an overnight curfew following the arrest of Minneapolis police officer Derek Chauvin, who faces murder charges in Floyd's death, captured on video beamed around the world.

The violence spread rapidly until just before midnight and into early Saturday, when hundreds of police officers, state troopers and armed National Guard troops fanned out into areas of vandalism and arson, confronting rioters with tear gas and orders to disperse.

The continuing havoc, which has spread to cities across America, has prompted rounds of recrimination and finger-pointing among state and local leaders about the law enforcement response, which in many parts of Minneapolis had seemed all but undetectable earlier Friday night.

Walz sought to calm the protesters earlier in a 1:30 a.m. news conference with Minneapolis Mayor Jacob Frey, both making emotional appeals to end the violence.

National Guard is 'all in'

"The absolute chaos — this is not grieving, and this is not making a statement [about an injustice] that we fully acknowledge needs to be fixed — this is dangerous," Walz said. "You need to go home."

Walz said he had talked to Floyd's family and that they agreed what was happening in Minneapolis was horrific and counterproductive.

The DFL governor has come under fire from Republicans in the Legislature calling for a more robust response. "They need to show the force, not have everything hidden behind the scenes," said Senate Minority Leader Paul Gazelka, R-East Gull Lake. "I'm glad that they called the curfew, but when people violate the curfew you have to arrest them."

Walz and the mayors of Minneapolis and St. Paul acknowledged that police, state patrol and National Guard soldiers were overwhelmed the past two nights by the extent of the rioting and vandalism, which state Public Safety Commissioner John Harrington estimated to involve "tens of thousands" of people.

Maj. Gen. Jon Jensen, adjutant general of the Minnesota National Guard, said that despite the largest show of force in state history Friday night, "it was not enough." He said the governor's full deployment order would mean "the Minnesota National Guard is all in."

Walz said he also has been in touch with military authorities in Washington to discuss logistical and intelligence support as authorities work to regain control of the streets in Minneapolis and St. Paul.

Staff writers Ryan Faircloth and Paul Walsh contributed to this report.