Voices continue to rise in protest against police violence, and on Sunday they belonged to the students.

In a demonstration organized by teens from Minneapolis high schools, about 150 people gathered Sunday afternoon outside the Minneapolis Central Library on Nicollet Mall, where high schoolers — black and white — delivered remarks and read poems exploring injustice and hope.

Then they marched — first across the Hennepin Avenue Bridge and then back downtown via the Third Avenue Bridge. They moved briskly, and police reported no incidents or arrests. Yet they held up traffic in the process and drew attention to their cause, chanting phrases like “Hands up/Don’t shoot” and “When I say Eric/You say … Garner!”

Their messages referred to the deaths of Michael Brown of Ferguson, Mo., and Eric Garner, of New York City, two black men killed in confrontations with police officers.

Passing a megaphone back and forth in the center of the crowd were two Southwest High students: Yonci Jameson, 16, and Laye Kwamina, 17.

Both had spoken earlier at the library, criticizing police behavior. Kwamina read a poem, raising the possibility of an unborn son who might be killed by an officer.

But that story line could change, too, Kwamina said afterward.

There’s hope, he said, in the nationwide protests that have followed the recent grand jury decisions not to indict the officers in the deaths of Brown and Garner.

“Never in my lifetime have I seen people come together so passionately to end police brutality,” Kwamina said.

Last Thursday, demonstrators in south Minneapolis marched onto Interstate 35W, shutting it down for the first time since protests against the Vietnam War.

Police in squad cars monitored Sunday’s hourlong march, which included a staged 4 ½ minute “die-in” in Brown’s honor outside the Hennepin County Government Center, and kept other motorists at bay.

At one point, when the march resumed along 5th Street just west of City Hall, a squad car sped around a distant corner with lights flashing to get in front of the marchers and ensure safe passage across an intersection.

At that point, the marchers were chanting, “Whose streets? Our streets!”

Among them was Dima Watkins, 17, a student at Washburn High who had addressed the crowd earlier.

In an interview, he likened the recent protests to the campaign blocking a proposed state constitutional amendment prohibiting gay marriage.

“This is going to be harder,” he said. “But it does not mean our actions are futile.”

Sunday’s rally was led by Maya Morales, 16, of Patrick Henry High, and drew students from across the city with postings on Facebook, Jameson said.

Morales was up front at the start of the march, as the protesters warmed up with a chant, “Hey, hey, ho, ho, this racist system has to go.”

When the march ended, Morales encouraged participants to keep delivering the message.

“Change doesn’t have to take 10 years,” she said. “But if it takes 10 years, it takes 10 years.”