MINNEAPOLIS - About 150 protesters were arrested 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 scattered a crowd of thousands gathered on the I-35W bridge in Minneapolis.


State officials say the trucker 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 on Sunday night. Chauvin is scheduled to appear in court June 8.


Earlier Sunday, officials gave an ominous warning about continued arson attacks, after 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 plateless car attempted to "douse the car itself and set it on fire," which is "not something you see on most traffic stops," Harrington said.


About 8:40 p.m., police began closing in on 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.


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 out of the truck.


Minneapolis police closed in and took the driver, who was injured, into custody. An Otsego 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 Bureau of Criminal Apprehension are investigating the incident as a criminal matter.


As far as officials can tell from Minnesota Department of Transportation cameras at the time, Harrington said the truck "was on the freeway already as we were closing the freeway." Twin Cities freeways were closed to traffic beginning at 5 p.m. Sunday. It does not appear he went around any barricades, Harrington said.


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."


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.


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.


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 such as "we honor you George" in the middle. They played Bob Marley songs and set out water and food.