BALTIMORE (AFP) - Protesters in Baltimore erupted in celebration Saturday and hundreds of people broke the city's curfew, a day after six police officers were charged over the death of an African-American man in their custody.

The death of 25-year-old Freddie Gray had sparked rioting and days of protests in the US East Coast port city over alleged police racism and brutality. But the mood on the streets was drastically different on Saturday, with people singing and dancing as they cheered the charges including second-degree murder and manslaughter laid against the six police officers - three of them black.

As calm gradually returned to the city, the governor of Maryland state urged residents to make Sunday a day of "prayer and peace".

"I pray that tomorrow will be a day of reflection and will serve as a foundation for how we all conduct ourselves in the days and months to come," Governor Larry Hogan said in a statement.

City police commissioner Anthony Batts echoed that sentiment, saying: "My hope is that we work towards a new level of partnership in all parts of our community as we move forward."

A string of killings of unarmed African-American men by the police in recent months have ignited protests across the country. Charges are rarely brought against officers.
Friday's charges had therefore come as a surprise to the city of 620,000, about an hour's drive north of Washington.

A spontaneous street party of thousands of people erupted in Baltimore on Saturday.

Demonstrators - white and black - also gathered at City Hall, the focal point of rallies in recent days. "I am so inspired and encouraged by what I see," Mayor Stephanie Rawlings-Blake told CBS television affiliate WJZ.

"I think that there's a lot of hope that in peace we can seek justice." After the rally, protesters marched toward the neighborhood where Gray was arrested on April 12. He died a week later from his injuries. "Whose streets? Our streets!" they chanted.

'Stop police brutality'

"It's been a frustration, what's going on. Now we want to stop police brutality, we want peace," Autumn Hooper, a 25-year-old African American woman, told AFP.

The death of Gray at the hands of police has reignited simmering resentment in the United States over law enforcement tactics, particularly in their dealings with African Americans.

In video recorded of the incident in Baltimore, Gray appeared to be in pain as he was hustled into a police van. He died seven days later with 80 per cent of his spine severed at the neck, lawyers for his family have said.

His death has prompted rallies in many other major American cities, including New York, Philadelphia and the capital Washington, in echoes of the protests that broke out across the United States last year over the fatal police shooting of an unarmed black teenager in Ferguson, Missouri.

'Shackled by his feet'

The medical examiner found that Gray's death was a homicide and Maryland state prosecutor Marilyn Mosby announced Friday an investigation found probable cause for criminal charges.

Mosby said Gray "suffered a severe and critical neck injury as a result of being handcuffed, shackled by his feet and unrestrained" inside a moving police van following his arrest.

Mosby - an African-American woman who is the daughter, granddaughter and niece of police officers - said Gray had been "illegally arrested" as "no crime had been committed."

Baltimore's police union condemned what it called "an egregious rush to judgment," as it defended the officers and expressed confidence they would be cleared.

While some expressed relief that the police officers had been charged, others cautioned that it was only the first step in a process that once again casts a damning spotlight on race relations in the United States.

Lawyer and activist Malik Shabazz pressed Mosby: "Don't (back) off" as he addressed a calm, mostly young, crowd under sunny spring skies.

He led demonstrators in a chant of "No justice, no peace!" Shabazz also urged Maryland's governor to end the curfew in Baltimore, which business owners say is hurting them seriously, and to order out National Guard troops.

"I ask respectfully, Governor Hogan, back up your troops," he said.

Maryland's branch of the ACLU, the largest US civil rights organisation, also said "the curfew no longer serves its intended purpose," in a statement.