Baltimore police have enforced a curfew for a third night, as new reports emerged over how the black man at the center of the latest US racial unrest sustained fatal injuries while in police custody.
Fresh protests had broken out in Baltimore and Philadelphia earlier over the death of 25-year-old Freddie Gray - the latest household name in the national debate over whether American police are too quick to use violence against blacks, especially young men.
As a 10:00 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, calm was restored and the streets were largely vacated.
The demonstrations 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.
Yesterday 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 the city following Gray's funeral.
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.
The circumstances surrounding his 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, WJLA, an ABC affiliate, cited "multiple law enforcement" sources as saying that a medical examiner found the spinal injury was caused when Gray 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 it was not immediately clear what propelled him 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.
