Between 50 and 100 activists closed down two blocks of downtown Minneapolis Wednesday night before marching to Hennepin County Government Center to protest the March shooting death of biracial youth Tony Robinson by a white police officer in Madison, Wis.

The march was organized by the Black Liberation Project, said member Vanessa Taylor.

A heavy police presence was on hand as protesters filled sections of South Seventh Street between Marquette and Hennepin avenues, directing traffic away from the group and seeking to maintain order in front of City Center and downtown hotels.

Protesters, holding a banner reading “Solidarity,” chanted their sympathy for Robinson and their displeasure at news that no indictment would be brought against the police officer.

On Tuesday, Dane County District Attorney Ismael Ozanne announced he would not file charges against the officer, Matt Kenny. Protests in Madison after the DA’s ruling were largely peaceful.

Many protesters in Minneapolis could be seen dousing their eyes with milk in an attempt to counteract the effect of chemical mace being sprayed. A 11-second video posted on Twitter apparently showing an Minneapolis officer spraying a chemical into a bandana-wearing protester’s face quickly went viral, garnering nearly 400 retweets before press time. One protester said she had been sprayed not by police but by a woman in the crowd apparently not affiliated with the rally.

Taylor said she was also maced while standing a few feet in front of one officer. Members picked up milk cartons at convenience stores along the route to relieve the burning.

The event culminated at the Government Center, where protesters linked arms.

“They put their hands on us. They maced us. They maced children …” Taylor yelled to the crowd. “If you are willing to mace our children, you do not think black lives matter.” Supporters of the Black Lives Matter group, which has spearheaded numerous earlier rallies in the Twin Cites, were also present at the Wednesday night gathering.

Minutes after the crowd dispersed, protesters lit up social media with complaints that a 10-year-old had been among those sprayed with the chemical.

The Minneapolis Police Department released a statement from Chief Janeé Harteau by 11:30 Wednesday night vowing to open a full investigation “into the concerns brought forth this evening.

“Our investigation will include gathering surveillance video and interviewing witnesses. I understand and appreciate people’s concerns and will gather the full set of facts as quickly as possible. I assure everyone this will be a thorough investigation.”

Another video showed the protesters burning two U.S. flags in front of the police station on Fourth St., as officers stood by and watched. The protesters chanted, “We don’t get no justice, they don’t get no peace.”