About 150 protesters were arrested near I-35W and Washington Avenue in downtown Minneapolis Sunday after they failed to heed the 8 p.m. curfew.

"Even peaceful protesters who are breaking curfew are subject to arrest. Please go home and stay there. Curfew is in effect in Minneapolis and St. Paul until 6 a.m." said a tweet from the state Department of Public Safety.

On a day when thousands of protesters marched peacefully, a near disaster struck. Just before 6 p.m., a tanker truck driver scattered a crowd of thousands gathered on the 35W bridge in Minneapolis.

State officials say the trucker, 35-year-old Bogdan Vechirko, may not have realized the highways had been closed. No injuries among demonstrators have been confirmed, they said.

At a news conference Sunday night, Corrections Commissioner Paul Schnell noted that Derek Chauvin, the former Minneapolis officer accused of murder in George Floyd's death, had been moved from the Hennepin County jail to Oak Park Heights state prison. He said concerns included COVID-19 and the expectation that a large number of people could be booked into Hennepin County jail tonight. He's scheduled to appear in court June 8.

Law enforcement and Minneapolis residents were on high alert into the early hours, even though ominous warnings about a new wave of arson attacks had not materialized as of the early hours of Monday.

Earlier Sunday, state officials said several caches of flammable materials were found both in neighborhoods where there have already been fires and "in cars we've stopped as recently as this morning," said John Harrington, state public safety commissioner. Some of the caches look like they may have been planted days ago and some only in the last 24 hours or so, he said.

Police are also finding stolen vehicles with plates removed that are being used to transport the flammable materials. Looted goods and weapons also have been found in the stolen cars, he said.

"The fact that we've seen so many of them in so many places now makes us believe that this is part of that pattern that shows that this in fact an organized activity and not some random act of rage," he said.

One person pulled over in Bloomington while driving a plate-less car attempted to "douse the car itself and set it on fire," which is "not something you see on most traffic stops," Harrington said.

He said it is critical that people stay home.

Shortly after 8 p.m., protesters on the Washington Avenue bridge over I-35W — some sitting on the ground with their bikes — were at a standstill as they encountered police lining both sides of the highway. The officers had moved up on the entrance ramps and were blocking people from returning to the road. Police did not advance on the marchers at that time.

About 8:40 p.m., police began closing in at a group of about 200 protesters clustered at Bobby & Steve's Auto World and set off several concussive devices. Ten minutes later, police announced over a loudspeaker that all protesters in the parking lot at Bobby & Steve's were under arrest and asked them to lie down. Minutes later, police who had encircled the crowd, started closing the circle and making arrests.

By 9:15, police had started loading arrested protesters onto buses. They remained peaceful and most said nothing as they were led past news crews.

"No justice no peace," shouted one woman being escorted to a bus. "We're doing it for America."

Even as protesters waited to be taken to jail, the positivity of the day endured.

"There's no reason to be super negative right now ... We've got to keep up that good energy, that good vibe," said Dakota Shelton-Norunner, a 19-year-old from Plymouth.

"He's pretty cool," Shelton-Norunner said of a State Patrol trooper nearby.

Later, the trooper asked Shelton-Norunner, "Does that bother you?" before adjusting the zip ties binding his wrists.

Douglas Golliday, a 65-year-old Fridley resident, still was waiting around 11 p.m. in the parking lot of Bobby and Steve's for a bus to take him and other protesters to jail.

"We need change," he said. "We need change ... If we don't fight for change we're not going to get it."

He was arrested along with his 44-year-old son, Robert Golliday. They've both been demonstrating since Tuesday.

"I'll be back here tomorrow in the march until the change the laws and we get equal rights," said Golliday, who is black.

Asked why it was important for him to protest, Robert Golliday said, "Because I'm a black man."

He spoke of the pain of seeing the video of Floyd die. "To hear a grown man call for his mama, it hurts."

Earlier in the day, witnesses on the 35W bridge over the Mississippi River said dozens of marchers were sitting or had taken a knee for a moment of silence when the truck came hurtling toward them and stopped halfway across the bridge. Then demonstrators swarmed the cab and appeared to drag the driver, Vechirko, out of the cab.

Minneapolis police closed in and took the driver, who was injured, into custody. The Otsego, Minn., man was being held on probable cause for assault. The state said it had no confirmation of any protesters being injured, but some may have sought medical attention themselves.

Harrington said between 5,000 and 6,000 people were on the bridge at the time. The State Patrol and the BCA are investigating the incident as a criminal matter.

Twin Cities freeways were closed to traffic beginning at 5 p.m. Sunday. As far as officials can tell from MnDOT cameras at the time, Harrington said the truck "was on the freeway already as we were closing the freeway."

State Corrections Commissioner Paul Schnell said at a later briefing that the truck went around a traffic barrier to stay on the road.

Drew Valle, a special education teacher at Minneapolis Washburn High School, said cars still driving on the roadway were going slowly to the right of the throngs of people when the truck came speeding toward the marchers.

"He wasn't stopping. He was beeping loudly and driving into a crowd of people," said Valle, visibly shaken. "That's the same kind of malice that brought us here. It's a callous disregard for someone's humanity."

Melanie Ramos of Minneapolis said: "A truck came. The horns were blaring. It was picking up speed. It was plowing down the highway into the protesters. It was the most terrifying thing I've ever seen."

Dominic Kerr said he could smell the fuel and hear it "sloshing around" as the tanker approached.

"He was coming about 30 mph. I know at least one person who definitely needs help," Kerr said.

In a Sunday evening news conference, Gov. Tim Walz described footage of the truck driving into the crowd as a "horrifying image" and said that it underscores the "volatile" nature of the situation here in the Twin Cities.

Walz said law enforcement responded immediately to "protect the peaceful protesters" and that there are no confirmed cases of injuries involving protesters at this time.

"I don't know the motives of the driver at this point in time," he said. "But at this point in time to not have tragedy and many deaths is an amazing thing."

Before the marches, Walz had ordered highways and interstates to start closing at 5 p.m. instead of 7 p.m..

Westbound Interstate 94 in St. Paul was shut down midafternoon as about 1,500 people left a rally at the State Capitol and marched toward Minneapolis before exiting on Lexington Parkway and returning east on University Avenue.

Charles Adams of Chicago was visiting his daughter in Minneapolis and joined one of the marches.

"It's mind-blowing," he said. "I really was impressed by the solidarity and the peacefulness of it. I hope that we would look in the mirror and realize that this is a real thing, and address it."

As curfew went into effect, hundreds were gathered in front of Cup Foods, the site of Floyd's death, to peacefully protest police. They commemorated Floyd with hundreds of flower bouquets arranged in a circle, and some painted images and phrases like "we honor you George in the middle. They played Bob Marley songs and set out water and food.

Ashley Gary of Minneapolis marched from Cup Foods on 38th and Chicago to the Washington Avenue Bridge with her three sons. She was proud, saying her youngest didn't complain most of the walk.

"We've been through Jamar Clark, we've been through Philando Castile and there was no justice whatsoever. We're tired of it, we are very tired. My son he's 16 and six feet tall and I don't want him to be taken as somebody bad because he's a bigger black man."

She added: "We teach our kids if you kill somebody, you go to jail. Society is teaching them, 'If you kill someone you can go home and put your feet up.' "

A group of protesters at 38th and Chicago began building barriers in anticipation of a police crackdown, but by 1 a.m. Monday, they were undisturbed.

Staff writers John Reinan, Pam Louwagie, Torey Van Oot, Briana Bierschbach, Andy Mannix, Maya Rao and Kim Hyatt contributed to this report.