Firefighters yesterday battled building fires in Baltimore sparked by rioting that erupted after the funeral on Monday of a 25-year-old black man who died after suffering a spinal injury in police custody.

Acrid smoke hung over streets where fire crews raced to contain damage from violence that broke out just blocks from the funeral of Freddie Gray and spread through much of West Baltimore.

The unrest – which saw looters ransack stores, pharmacies and a shopping mall and clash with police in riot gear – was the most violent in the US since Ferguson, Missouri, was torn by gunshots and arson late last year.

Police said 15 officers were injured, six seriously, on Monday.

Gray’s death gave new energy to the public outcry over police treatment of African Americans that flared last year after police killings of unarmed black men in Ferguson, New York City and elsewhere.

US President Barack Obama yesterday called on police departments across the country to do some “soul-searching” on how they handle African-American suspects after race-related rioting erupted in Baltimore.

Obama said it was important for police departments to recognise that some of them have a problem in how they deal with criminal suspects of colour.

“There are some police who aren’t doing the right thing,” he said. Rather than close ranks, he said, some police chiefs have recognised “they’ve got to get their arms” around the problem.

Police forming a line during clashes with protesters near Mondawmin Mall after Freddie Gray's funeral.

The violence appeared to catch city officials and community leaders somewhat off-guard after a week of mostly peaceful protests following Gray’s death on April 19.

Maryland Governor Larry Hogan, ex Republican, declared a state of emergency on Monday and the National Guard was arriving in the city. A one-week curfew was also imposed in the largely black city starting yesterday night, with exceptions for work and medical emergencies.

Answering criticism of not responding quickly enough to Monday’s events, mayor Stephanie Rawlings-Blake told CNN: “This was an incident that sparked this afternoon ... I think it would have been inappropriate to bring in the National Guard when we had it under control.”

Blake yesterday said on Twitter that she was beginning her day with a survey of the most damaged areas.

On Monday, youths threw rocks and bricks at police. Rioters smashed car windows outside a major hotel and twice slashed a fire hose while firefighters foughta blaze at a CVS pharmacy that had been looted before it was set on fire.

Firefighters responding to a fire at a CVS pharmacy on Pennsylvania Avenue in Baltimore.

Firefighters on Monday evening battled a blaze that consumed a church’s senior center under construction in East Baltimore. City officials said it was not known if the fire was connected to the unrest.

Police made at least 27 arrests and Baltimore schools were closed yesterday. An Orioles baseball game was cancelled and businesses and train stations shut down in the city of 620,000 people 64km from the nation’s capital. Gray was arrested on April 12 when running from officers. He was transported to the police station in a van, with no seat restraint and suffered the spinal injury that led to his death a week later. A lawyer for Gray’s family says his spine was 80 per cent severed at the neck while in custody.

Six officers have been suspended, and the US Justice Department is investigating for possible civil rights violations.

Much of Monday’s rioting occurred in a neighbourhood where more than a third of families live in poverty.

After the looting began, pastors and other local figures took to the streets to try to prevent violent clashes between black youth and police and Gray’s family renewed their pleas for peaceful demonstrations.

Riots over police brutality and race issues have gripped US cities before.

In the 1992 Los Angeles riots, more than 50 people were killed in violence set off by the acquittal of four police officers who beat black motorist Rodney King. In 1968, dozens died in riots, including several in Baltimore, after the assassination of civil rights leader Martin Luther King Jr.