The scene after the gunfire. (Stephen Maturen/Getty Images)

MINNEAPOLIS — Authorities on Tuesday said they had three people in custody after someone opened fire on people near a “Black Lives Matter” rally against a recent police killing of an unarmed black man, a day after five people were wounded in a shooting not far from a police building that has been the epicenter of protests here.

In Chicago, meanwhile, officials were preparing for several days of possible protests, as prosecutors on Tuesday charged a police officer with murder and officials released a graphic video depicting the shooting.

The churning situations in two cities more than 400 miles apart came during a period of heightened racial tension and intense scrutiny for how police use force with minorities, something repeatedly brought to the fore as high-profile deaths of black men or boys during and after encounters with police have given way to demonstrations and unrest across the country. In some cases, the promise of a disturbing video brought scores of people to the streets; in other places, like Minneapolis, the protests were driven by a demand that footage be released.

[Chicago police officer charged with first-degree murder in shooting of black teenager]

Protesters in Minneapolis were not daunted by the previous night’s gunfire, and even as police said they were seeking three white suspects, demonstrators continued to gather at the Minneapolis Police Department’s 4th Precinct, as they have since 24-year-old Jamar Clark was shot earlier this month.

Late on Monday night, police said they received multiple 911 calls after gunfire that wounded five people a block away from the 4th Precinct. All five people, who had been protesting at the police building, suffered non-life-threatening injuries, officials said.

Black Lives Matter Minneapolis said in a post on Facebook that “white supremacists” attacked the group “in an act of domestic terrorism,” and the group vowed not to be intimidated.

Minneapolis police said Tuesday that they had arrested two men: A 23-year-old white man taken into custody in Bloomington, a nearby city, and a 32-year-old Hispanic man found in Minneapolis. Authorities said they were still seeking additional suspects and did not identify the men in custody.

Later in the day, police said they had released the 32-year-old Hispanic man after it was determined he was not at the shooting scene. They also said they had a total of three white men in custody. In addition to the 23-year-old arrested in Bloomington, the Minneapolis police said a a 26-year-old and a 21-year-turned themselves into investigators.

Protesters said that the shooting occurred after a group of people — three men and a woman, all wearing ski masks — were seen filming the activity. The people in ski masks went down Morgan Avenue, and a group followed them, but some kind of fight ensued and gunshots rang out, said Henry Habu, who has been at the protests since Sunday.

Habu said that protesters had been told to watch out for white supremacists wearing masks or camouflage clothing, and said the group filming the demonstrations matched those descriptions.

Several people involved in the demonstrations — including a Black Lives Matter organizer and the NAACP Minneapolis chapter president — have said the person or people who opened fire were white supremacists. Authorities have not confirmed those claims.

After the gunshots at 10:40 p.m. on Monday, police said dozens of officers rushed to the scene and began investigating. Demonstrators rushed to tend to the injured, and others flocked to to the area.

“It was very somber,” said John Jacobson, who said he had arrived 30 minutes later after seeing a Black Lives Matter post on Facebook. “Like a wake, and you’re looking for familiar faces.”

One demonstrator was shot in the leg and was among “four boys on the ground,” said Carrie Brown. “He just kept saying, ‘Don’t leave me, don’t leave me.'”

Federal authorities said Tuesday that they knew about the shooting and were working with local police during the investigation.

“The Department of Justice is aware of the incident and is coordinating with the Minneapolis Police Department to assess the evidence and determine if federal action is appropriate,” the department said in a statement.

The rallies had been sparked by the Nov. 15 shooting of Jamar Clark. Police said that Clark was the suspect in an assault and interfered when paramedics tried to treat the assault victim.

“At some point during an altercation that ensued between the officers and the individual, an officer discharged his weapon, striking the individual,” the Minnesota Department of Public Safety said in a statement.

The officers involved were Mark Ringgenberg and Dustin Schwarze, both of whom have been with the Minneapolis police for a little over a year and have each been officers for seven years, said the Bureau of Criminal Apprehension, the state agency investigating the shooting. Police have not said which officer fired the fatal shot.

The FBI has announced that it will conduct its own investigation, while the U.S. attorney’s office in Minnesota and Justice Department prosecutors will review evidence to see whether any civil rights statutes were violated.

Some witnesses have said that Clark was handcuffed when he was shot, while police have said that did not appear to be the case. Drew Evans, superintendent of the Bureau of Criminal Apprehension, has said that authorities were still working to determine whether Clark was handcuffed when he died.

Demonstrators have called on police to release video footage of the shooting. Evans has said that there is no complete video of the shooting, though investigators have multiple videos that he said related to the encounter.

The shooting on Monday occurred the night before the one-year anniversary of a Missouri grand jury’s decision not to indict Darren Wilson, a white police officer in Ferguson, Mo., for fatally shooting of Michael Brown, an unarmed black teenager. That decision helped reignite powerful frustration about the way African Americans are treated by police, and like a similar decision in New York the following month, prompted heated protests.

On Sunday, meanwhile, a vigil marked the first anniversary of the death of Tamir Rice, a 12-year-old fatally shot while playing with a toy gun in a Cleveland park. While numerous other incidents in the interim have resulted in decisions about whether or not the officers should face charges, that case remains open and no decision has been announced, a length of time that demonstrators have criticized.

In Chicago, attention was squarely focused on a shooting that occurred more than a year before Clark’s death. Prosecutors announced that they had charged Jason Van Dyke, a Chicago police officer, with first-degree murder for shooting McDonald in October 2014. The teenager was holding a knife, which police said he had used to slash the tires of one squad car when he encountered officers.

Van Dyke was the only officer to fire at McDonald during the October 2014 incident, officials say. He was on the scene near McDonald for less than 30 seconds before he began firing a total of 16 shots, said Anita Alvarez, the state’s attorney for Cook County, Ill.

The video footage, released on Tuesday evening and broadcast widely across social media, showed McDonald carrying a knife on what appears to be a major road when Van Dyke opened fire. The video also shows Van Dyke continuing to shoot after McDonald falls to the street.

Van Dyke’s attorney has said the officer feared for his life when he opened fire.

But the officer’s actions “were not a proper use of deadly force,” Alvarez said during a news conference Tuesday.

“He abused his authority, and I don’t believe the use of force was necessary,” Alvarez said. She also said: “With these charges, we are bringing a full measure of justice that this demands.”

In April, the Chicago City Council approved a $5 million dollar settlement to McDonald’s relatives. But some in the community say they are angry it took Alvarez’s office so long to charge Van Dyke.

“There is no way this length of time should have gone on so long when the video showed all this evidence,” Michael Pfleger, a Catholic priest in Chicago, said Tuesday. “Shame on them for being so late.”

Protesters vowed to demonstrate through the long holiday weekend.

“Michigan Avenue is going to be very uncomfortable,” said Quovadis Green, 24. “We’re going to hit them from every angle and every neighborhood. We got show people that no one is above the law.”

Meanwhile, protesters in Minneapolis vowed to keep returning to the 4th Precinct, though Clark’s family has called for an end to the protests after Monday night’s shooting.

In a message of defiance a crowd of hundreds, diverse in age and rage poured into downtown Minneapolis on Tuesday afternoon. Organizers declared it a show of force, and many of those who marched said that the prior night’s shooting drove them into the streets, not out of them.

“I’m out here to make sure those cowards know that they didn’t scare anybody,” said Demetrius Pendleton, 46, who runs a local homeless shelter. “We want to see justice, and we won’t stop until we get it.”

They marched through downtown, as crowds of white men in suits stood in windows of the restaurants during happy hour, many pulling out their phones to record the procession.

“We need justice for our people,” said Takyezia Lee, a 15-year-old high school student who was attending her first protest after watching activism play out nationally across the nation for the last year. “I support everything Black Lives Matter stands for so I decided it was time to join in.”

The sights and sounds were essentially identical to those that have played out in dozens of American cities in the year since Brown was killed. The crowd danced to Kendrick Lamar’s “Alright,” shouted out the names of a number of those killed by police in the last year — Brown, Tamir Rice, Walter Scott — and endlessly chanted, “No justice, no peace, prosecute the police.”

The Minnesota protesters demands were also identical to things said during protests in Ferguson and Cleveland and Baltimore.

“We want justice,” said Pastor Jayme Ali, a local minister who marched near the front of the crowd.

Ali, 44, was born and raised here, and said it is time this city address issues of racial inequity, especially in policing. While she had attended many of the first days of protests, she had not come out for three days because of an illness.

But the shooting of the five activists on Monday night inspired her back into the street. She wanted to show that she wasn’t afraid. As she marched from the police station to City Hall, her hands griped a homemade cardboard sign with a warning for the nation: “This could be your city next.”

Berman reported from Washington. Lindsey Bever and Michael E. Miller in Washington and Mark Guarino in Chicago contributed to this report.

Related:

The Post’s database on police shootings

How The Post is tracking these shootings

Unarmed and Black: unarmed black men are seven times more likely than whites to die by police gunfire

Current and former police officers describe tension in current environment