In the tense hour after a 10 p.m. curfew went into effect Wednesday night in Brooklyn Center, law enforcement cleared a dwindling crowd of protesters outside the city's police headquarters, arresting 24 people, authorities said.

For a fourth night, hundreds had gathered outside the fenced-in Brooklyn Center Police Department, most of them peaceful, but some hurling objects at law enforcement, which included National Guard members, State Patrol officers and Hennepin County sheriff's deputies.

Even before the curfew took effect, several dispersal orders were issued as water bottles, milk jugs, bricks, rocks, fireworks and other objects thrown at officers led authorities to declare an unlawful assembly. By 10:30, many protesters had left after a fourth dispersal order, but those who remained grew tense and verbally defiant as sirens sounded and law enforcement officers congregated en masse nearby.

Operation Safety Net, a public safety coalition formed to respond to incidents related to the Minneapolis trial of former police officer Derek Chauvin, accused of killing George Floyd, reported early Thursday that the streets around the police headquarters were being cleared and that some arrests were being made.

John Harrington, the state's Department of Public Safety commissioner, said at a midnight news conference that many activist groups planning to protest had told law enforcement that they did not want trouble, but that a few protesters did create problems.

Despite the large number of law enforcement, the clearing operation appeared to be much calmer than one that occurred late Tuesday. Another sharp contrast from Tuesday was that no tear gas was used, perhaps in response to a denunciation by Brooklyn Center Mayor Mike Elliott of its use, which also plagued city residents.

Hennepin County Sheriff Dave Hutchinson said at the late-night news conference that almost all of those arrested were from outside Brooklyn Center.

State Patrol Col. Matt Langer said at the news conference that 24 people had been arrested for rioting and curfew violations, a much lower total than Tuesday night's. "The number one tool we wanted to use tonight was patience," he said, adding that Wednesday's crowd lacked the "entrenchment mentality" of previous gatherings.

For a second night in a row, there was no looting, authorities said.

Some protesters, toting umbrellas and other shields against pepper spray or tear gas, set up wooden barricades in the streets. Officers responded to thrown objects by firing pepper spray and marking paint. Some demonstrators blasted Pink Floyd's "Another Brick in the Wall" toward the police station.

Earlier, many of the protesters demanded that more serious charges be brought against former police officer Kimberly A. Potter, who fatally shot Daunte Wright, 20, on Sunday. She has been charged with second-degree manslaughter.

"What she did is murder! How do you not know your Taser from your gun?" asked Loretta VanPelt of the Twin Cities Coalition for Justice 4 Jamar, before the rally began at 7 p.m.

Since Sunday, hundreds of protesters have gathered nightly outside the police station. On Tuesday night, more than 60 people were arrested after law enforcement moved in with heavy force against 800 to 1,000 protesters.

VanPelt and others questioned the need for the heavy police presence.

"How are we the violent ones? They're the ones ready for war," she said of the National Guard members and riot police behind fortified fences across the street.

At a news conference Wednesday afternoon, Elliott urged protesters to remain peaceful and abide by the curfew, but he also made it clear that he didn't agree with policing tactics against protesters and the members of the media, who were asked to leave Tuesday night.

"I did initially ask for mutual aid," he said. "The operation last night was under the auspices of the Sheriff's Office. And that's all I'll say about that."

Elliott was asked whether this was a "democratic crisis" given that he doesn't agree with law enforcement's response of tear gas and pepper spray but only has control over his own officers.

He said most of his officers were responding to 911 calls across the city. "Our Police Department was not engaged in using any pepper spray or gas," he said, adding that there needs to be a different approach to policing. "Gassing is not a humane way of policing."

Many at Wednesday's rally compared Potter's case to that of former Minneapolis police officer Mohamed Noor's case, saying Potter should also face murder charges.

"What do we want? Murder charges! What she did was murder," Jaylani Hussein, executive director of the Minnesota chapter of the Council on American-Islamic Relations told the crowd. "How is it possible Mohamed Noor got murder charges and not her?"

Noor was convicted of third-degree murder and second-degree manslaughter for fatally shooting Justine Ruszczyk Damond, who called 911 to report a possible sexual assault in the alley behind her house in 2017. He is serving a 12 ½-year prison sentence.

Noor was the first former Minnesota police officer found guilty of an on-duty murder.

In Duluth on Wednesday, nearly 150 people filled a downtown street, chanting, "No justice, no peace" and "Black lives matter."

"We're being told by police, 'Put your hands up' and you're still killing us," organizer Lamarquita Leach said. "There's so much in the system that needs to change. We'd have to start a whole new system."

Staff writers Kim Hyatt and Brooks Johnson contributed to this report.