Baltimore residents yesterday began to clear the wreckage of rioting and fires that erupted after the funeral of a 25-year-old black man who died in police custody, while the city's mayor defended local law enforcement's light initial response.

Acrid smoke hung over streets where violence broke out just blocks from Freddie Gray's funeral and spread through much of the poor West Baltimore neighborhood. Nineteen buildings and 144 vehicles were set on fire, and 202 people were arrested, according to the mayor's office.

Police said 15 officers were injured, six seriously, in Monday's unrest, which spread throughout the city as police initially looked on but did not interfere as rioters torched vehicles and later businesses.

Looters had ransacked stores, pharmacies and a shopping mall and clashed with police in riot gear in the most violent unrest in the United States since Ferguson, Missouri, was torn by gunshots and arson in late 2014.

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

National Guard troops yesterday began to stage around the city, including in front of the police station where officers were bringing Gray at the time he was injured.

Maryland Governor Larry Hogan, a Republican, declared a state of emergency on Monday and Rawlings-Blake, a Democrat, imposed a one-week curfew in the largely black city starting Tuesday night, with exceptions for work and medical emergencies.

Gray was arrested on April 12 while 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 percent severed at the neck while in custody.

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