Image copyright AP Image caption Police have been under pressure to make their findings known

Police in the US city of Baltimore say that a van transporting Freddie Gray made a previously undisclosed stop while en route to the police station.

Gray suffered fatal and unexplained spinal injuries while in police custody, sparking two weeks of protests that turned violent earlier this week.

On Thursday, there were rallies in Baltimore, Philadelphia and Cincinnati.

A national debate over the use of lethal police force has been going on since last summer.

Police investigating Gray's death said they found out about the new van stop from a security camera.

"We discovered this new stop based on our thorough and comprehensive and on-going review of all CCTV cameras and privately owned cameras," Deputy Police Commissioner Kevin Davis said.

"This new stop was discovered from a privately-owned camera."

The new video was filmed by a CCTV camera outside a small Korean food shop.

The shop's owner, Jung Hyun Hwang told the Associated Press news agency that police officers visited last week to make a copy of the recording - which was later lost when the shop was looted during the riots.

Mr Hwang said he had not viewed the recording and did not know what it showed.

Investigators have now handed over their inquiry into Gray's death to the state's attorney's office.

The city's top prosecutor, Marilyn Mosby, will now decide whether to take the case to a grand jury to seek an indictment of any of the six officers involved.

'Not out of the woods'

After two nights of violent protests in Baltimore, Thursday was relatively calm. The city is still under a curfew requiring people to be off the streets by 22:00 (02:00 GMT).

Visiting the city earlier in the day, Maryland Governor Larry Hogan said the city was "not out of the woods yet".

"There are a lot of people that have legitimate frustrations that are peacefully protesting and we want to protect those people and their right to express their feelings," he said.

"But we're also concerned about their safety because there are other people who just want to cause trouble."

Image copyright Getty Images Image caption Philadelphia was the latest US city to hold a protest

Image copyright AP Image caption Members of the National Guard have been on patrol in Baltimore

Image copyright AP Image caption Various police vehicles were set alight during the riots

Gray was injured when arrested in Sandtown on 12 April. He lapsed into a coma and died a week later.

Mobile phone video from a bystander shows two officers dragging Gray into the van by the arms.

According to the police timeline of the arrest, the van took 30 minutes to take him to the police station, where paramedics were called.

While in the van, Gray was requesting medical attention which he was wrongly denied, police have admitted.

They also acknowledged that he was not secured in the van by a seatbelt, which contravenes department policy.

According to a local ABC station, quoting unnamed sources, the medical examiner has concluded that Gray received his injuries inside the van, not when he was first arrested.

Previously, police had said the van made three stops, including one to put him in leg irons and another to pick up another prisoner. The new stop makes four in total.

Five of the six officers involved in the arrest gave statements to investigators the day Gray was injured. All six have been suspended.

A separate investigation by the US department of justice is also under way.

Police timeline of Freddie Gray's arrest

Image copyright Murphy, Falcon & Murphy

Sunday, 12 April, 08:39: Officers approach Gray and he flees on foot

Officers approach Gray and he flees on foot 08:40: Gray arrested on corner of Presbury Street, Sandtown

Gray arrested on corner of Presbury Street, Sandtown 08:42: Police request a van

Police request a van 08:54: Van departs with Gray inside, conscious and speaking

Van departs with Gray inside, conscious and speaking 08:54-09:24: Van makes a total of four stops between arrest and police station arrival

Van makes a total of four stops between arrest and police station arrival 09:24: Police request paramedics to take Gray to hospital

What we know about Gray's death