People seeking racial justice and rebuilding for Baltimore planned a day of prayer and healing, even as others chafed under a curfew set to expire early Monday. City leaders refused calls to lift the curfew following the city's top prosecutor's announcement that charges had been filed against six officers accused of fatally injuring an unarmed black man in police custody.

On Friday State's Attorney Marilyn Mosby filed charges against six police officers involved in the arrest, transport and fatal injury of Freddie Gray, who died a week after suffering a broken neck while inside a police van, she said.

At the demonstration on Saturday that was billed as a "victory rally," speakers expressed gratitude to Mosby for her decision.

"Every prosecutor should have such backbone," said Malik Shabazz, president of Black Lawyers for Justice and one of the demonstration's organizers. "Every prosecutor should have such spine."

Mosby said Gray's neck was broken because he was placed head-first into a police van while in handcuffs and later leg shackles where he was left to slam against the walls of the small metal compartment. Police said the officers who arrested Gray ignored his cries for help because they thought he was faking his injuries. He was repeatedly denied medical attention.

Mosby deemed the death a homicide. After Gray's arrest Caesar Goodson, who was the driver of the transport van and who is facing a second-degree murder charge, made several stops before arriving at the police station and calling an ambulance. While some video footage of those stops is available, a camera inside the police transport van was not recording during Gray's ride, according to police.

Friday's charges were preceded by nearly two weeks of angry protests and demonstrations that on Monday night gave way to riots in the streets of Baltimore, prompting officials to call in the National Guard and implement an emergency curfew. Gov. Larry Hogan said in a news release Saturday afternoon that 578 Maryland State Troopers and other allied law enforcement officers were in the city. He also said 283 law enforcement personnel were in from Pennsylvania and 149 from New Jersey.

The 10 p.m. curfew, which was ordered Tuesday after a night of violence, looting and arson, has drawn harsh criticism from the city's residents.

The Maryland chapter of the ACLU sent a letter to Mayor Stephanie Rawlings-Blake on Saturday alleging that the curfew is "being enforced arbitrarily and selectively" to break up peaceful protests and prevent media outlets from providing accurate coverage of police activity.

"The curfew is having a dramatic effect on the ability of Baltimore residents to simply go about their daily lives free from fear or arbitrary arrest," the letter read, adding that it's also "the target of protest and the source of new problems rather than a solution."

As of 11 p.m. on Saturday, about 20 had been arrested, including one that was hit with a blast of pepper spray and was later taken away in an ambulance.

The curfew is slated to expire at 5 a.m. on Monday.

Hogan has called for a statewide "Day of Prayer and Peace" on Sunday.