AKIPRESS.COM - A state of emergency has been declared in the US city of Baltimore as protesters clash with police after the funeral of a 25-year-old black man who died a week ago from a spinal injury suffered in police custody.

The riots broke out just a few blocks from the site of Freddie Gray's funeral and then spread throughout other parts of the city, ABC news reports.

At least 15 police officers were injured, a police spokesman said, as authorities in riot gear cordoned off streets.

Hundreds of rioters looted businesses and set buildings on fire. Police said they had arrested about 27 people.

Television images showed a mob of rioters jumping on the top of a police car, after teenaged crowds ignored calls to disperse and clashed with a line of hundreds of police.

Rioters also cut a fire department hose while firefighters fought a fire at a pharmacy looted earlier, Baltimore police said.

"Right now we're seeing [an] unprecedented type of violence throughout the city. Mainly towards the west side of Baltimore," Baltimore police department's chief of patrol Darryl De Sousa said.

"We're not going to tolerate that. The police department is not going to stand for that. We're fully deployed at this point.

"We cancelled leave for all of our police officers, so they're deployed on the streets as we speak."

A large fire consumed a senior centre under construction near a church in East Baltimore, television reports showed, but it was not immediately clear if it was related to the riots.