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Thousands filled a grassy plaza across from Baltimore’s City Hall Saturday, as speakers praised the city’s top prosecutor for quickly moving forward with charges against the six police officers they see as responsible for the death of a 25-year-old black man who died from a spinal injury in their custody.

The peace was a striking contrast to the demonstrations the past two weeks at the same plaza. Crowds of angry protesters demanded that the city’s leaders heed their cries for justice. Earlier this week, protests turned into looting, rioting and arson.

Friday morning, just four days after the civil unrest, State’s Attorney Marilyn Mosby announced the criminal charges against the officers ranging from assault to murder in the death of Freddie Gray, whose name has become a rallying point against police brutality and socio-economic inequality in American cities.

"To the youth of the city," Mosby, 35, said as she announced the charges. "This is a moment. This is your moment. ... You're at the forefront of this cause and as young people, our time is now."

Organizers billed Saturday’s demonstrations as a “victory rally” as thousands of people made their way through the streets.

Chants of "no justice, no peace, no racist police" echoed and crowds of people, black and white, young and old, carried homemade signs calling for peace, as well as printed ones asking for justice. Others wore T-shirts that read, "Black Lives Matter," a slogan many have taken up in the fight.

"I think it has to do with Ms. Mosby living here in West Baltimore: they took seriously the sentiment of the youth," Kustanya McCray, a 41-year-old Baltimore resident who joined thousands of people at the demonstration, told The Associated Press. "Our city council, the mayor_they're all from here. They've lost family members to violence. They understand what's been happening. They understand they have no choice now."

The National Guard was called in to help police enforce a nightly curfew with heavily armed troops riding in armored vehicle. Around 3,000 National Guardsmen and law enforcement officials flooded the streets.

As of 11 p.m. on Saturday, a handful of people had been arrested, including one that was hit with a blast of pepper spray and later taken away in an ambulance.

Mosby said the police officers have no reason to stop or chase after Gray and said his neck was broken because he was handcuffed, shackled and placed head-first into a police van, where he was left to slam against the walls of the small metal compartment.

In Baltimore, before the racially and economically diverse crowd in City Hall plaza, Black Lawyers for Justice president Malik Shabazz praised Mosby for her decision, and called on the citizens of Baltimore to protect her.

"Every prosecutor should have such backbone," he said. "Every prosecutor should have such spine.

"We've always got the cuffs on us," he continued, "now the real criminals have the cuffs on them. Make sure no harm comes to this black woman who is prosecuting these police officers, because if any harm comes to this prosecutor while she is prosecuting this case we will hold Baltimore and America thoroughly accountable."

Earlier in the day, demonstrators gathered in Sandtown, the poor, predominantly black West Baltimore neighborhood where Gray was raised and arrested. Among the throng was Kweisi Mfume, the former congressman and president of the NAACP, who said the charges are a response to the passion and fury of young Baltimore residents.

"This current generation has realized that it has to shape its destiny and not wait for it to be shaped," Mfume said. "I think now they're starting to come to grips with the enormity of this and what they have caused to take place nationwide, and are embracing the fact that perhaps, this is our civil rights movement."

The Associated Press contributed to this report