The Minnesota State Patrol said more than 200 protesters shut down Interstate 94 in St. Paul for hours on Saturday night to protest last week's killing of Philando Castile, 32, in a St. Paul suburb. Officers were hit with rocks, bottles, concrete, construction materials and fireworks, police said.
The city's mayor and a protest leader both decried the violence, which injured 21 officers and led to 102 arrests. St. Paul police said one officer suffered a broken vertebrae when a concrete block was dropped on his head during the protest on the interstate.
"We will not tolerate the kind of shameless violence we saw throughout the course of the night," St. Paul Mayor Chris Coleman told a news conference. "This doesn't honor anyone's memory."
The call for demonstrators to remain peaceful came as officials grappled with a wave of demonstrations against police use of force that has swept the country in the past week.
At a spontaneous march in Dallas on Thursday, a U.S. military veteran shot and killed five police officers, sending a chill through law enforcement as well as those involved in the mostly peaceful demonstrations.
The protests follow the shooting of Castile as well as Alton Sterling, 37, in Baton Rouge, Louisiana.
Police arrested 102 people in Baton Rouge on Saturday night and Sunday morning, mostly for misdemeanors for not leaving a major thoroughfare known as Airline Highway. Those arrested included DeRay Mckesson, an activist and former Baltimore mayoral candidate, officials said.
Louisiana Governor John Bel Edwards said he was proud of how the police had handled the protests so far, saying law enforcement had responded in a "moderate" manner. He also said the vast majority of protesters had acted lawfully and nonviolently.
Edwards said, however: “It is not ... appropriate to allow them to simply block a major thoroughfare like Airline Highway."
Protesters from Louisiana or out of state will not be allowed "to incite hate and violence, to engage in unlawful activities," Edwards told a news conference. "Now I want to be very clear. That will not be tolerated."
In St. Paul, Rashad Turner, leader of the local chapter of the Black Lives Matter group, told WCCO-TV that the throwing of rocks and bottles at officers was disturbing. He blamed outside agitators for the violence, not the protesters on the freeway.
"It's ridiculous. It cannot happen. It's not what we do here in St. Paul," Turner said. "It does not honor Philando Castile."
Authorities said 50 protesters were arrested on the Minnesota interstate and 52 others later on a street near the governor's mansion, the site of most of the protests since Castile was shot on Wednesday.
"Protesters last night turned into criminals," St. Paul Police Chief Todd Axtell said. "And I am absolutely disgusted by the acts of some, not all, but some."
Some 300 people attended a peaceful protest on Sunday afternoon at the St. Anthony Police Department. St. Anthony police patrol the Falcon Heights suburb where Castile was shot.
In Baton Rouge, the capital of Louisiana, police said protests outside their headquarters appeared to be becoming more violent as protesters arrived from out of town.
After his arrest, Mckesson was booked on a misdemeanor charge of obstructing the highway and released from the East Baton Rouge Parish jail, according to the sheriff's website.
Baton Rouge police confiscated three rifles, three shotguns and two pistols at Saturday night's protest and were wearing helmets, shields and body armor.
Police said those arrested ignored repeated orders to stay out of the street, while demonstrators said officers charged into the crowds seemingly without any obvious provocation.
"The only people who were violent last night were the Baton Rouge Police department," Mckesson told reporters after his release. "The protesters remained peaceful, both here and across the country."