WASHINGTON (AFP) - Baltimore streets were largely calm on Thursday as an emergency curfew set in for a third night, following hours of protests over the death of an African-American man who died while in police custody.
Protests had broken out in Baltimore and spread to Philadelphia earlier in the day over the death of Freddie Gray, as fresh claims emerged as to how he sustained fatal injuries while detained by police.
But as a 10 pm curfew began in Baltimore, officers formed a cordon and engaged in a brief but mostly non-violent confrontation with a handful of protesters.
Afterwards, the streets were largely vacated and only police and journalists remained.
Baltimore has taken centerstage in the latest bout of protests in the United States over alleged police brutality and racism against blacks, mainly young men.
The demonstrations there echo protests that erupted in a St Louis suburb last year when a white policeman shot dead an unarmed black teenager, and then flared again in major US cities when a grand jury declined to indict the officer.
On Thursday, around 600 people marched in Baltimore, a city of 620,000 an hour's drive from Washington that has witnessed some of its worst unrest in decades.
But there was no immediate return to the scenes that made worldwide headlines on Monday when violence and looting shook Baltimore following Gray's funeral.
Meanwhile, Philadelphia also saw protesters demanding justice for Gray and an end to what demonstrators said is overly aggressive policing, particularly in confronting black Americans.
About 600 people gathered in the "City of Brotherly Love," police said, in what was a mostly peaceful march. But a hardcore element briefly clashed with officers when they attempted to take the rally onto a freeway.
Dozens of protesters jostled with police, and there were two arrests, CNN said from the scene. But as night fell, it reported that only around 100 demonstrators remained.
On Wednesday, thousands of demonstrators hit the streets in Baltimore, New York - where police made 143 arrests - Washington and Boston.
Gray died with 80 per cent of his spine severed at the neck, lawyers for his family say, portraying him as just the latest young African American to die at the hands of the police in the United States.
- New claims emerge -
The circumstances surrounding Gray's April 12 arrest and how he sustained the injuries that killed him a week later remain murky and the subject of intense speculation.
Adding to the simmering anger on the streets, WJLA, an ABC affiliate, cited "multiple law enforcement" sources as saying that a medical examiner found that the spinal injury was caused when he slammed into the back of the police transport van after his arrest, breaking his neck.
A head injury he suffered matches a bolt in the back of the van, the report said, stressing that it was not immediately clear what propelled him into slamming into the back of the vehicle.
Adding to the intrigue, police revealed that the van made a previously undisclosed stop between when Gray was arrested and when the vehicle arrived at the police precinct.
Baltimore Deputy Police Commissioner Kevin Davis did not elaborate on the significance of this.
An attorney for Gray's family, Mary Koch, told CNN that she had "no way of validating the information" and that a cause of death had not yet been rendered by the medical examiner.
Baltimore Police Commissioner Anthony Batts said that "people should take a deep breath to wait for the entire information and hopefully these leaks won't poison what's happening."
Police and Gray's family have repeatedly appealed for calm and an emergency nighttime curfew, starting at 10.00 pm and running till 5.00 am, remains in place and will continue over the weekend, when large demonstrations are anticipated.
Since Monday's riots, a total of 98 Baltimore police officers have been injured, of whom 43 required emergency medical treatment.
Detectives probing Gray's death have handed their investigation over to prosecutors, but Batts urged people not to rush to conclusions.
"I understand the frustration, I understand the sense of urgency, and so has the organization and that is why we have finished (the probe) a day ahead of time," Batts said.