Demonstrators and police clashed briefly in a second night of protests in the US city of Baltimore, where a curfew has been imposed to quell rioting triggered by the death of a black man in police custody.

Police used tear gas canisters and pepper balls against at least 200 protesters on Tuesday night in order to enforce the citywide curfew from 10pm to 5am.

But Al Jazeera’s Gabriel Elizondo, reporting from the city in Maryland state, said that there was little incidence after the brief clashes.

“There were very brief clashes with police and about 200-300 protesters that refused to listen to police orders to disperse. Some tear gas was used but it was fairly minor overall,” he said.

He added that most residents in the city did obey the curfew.

Larry Hogan, the governor of the state, said 2,000 National Guard members and 1,000 police officers would be in place overnight.

Violent protests erupted on Monday, shortly after the funeral for a black man who died on April 19 after he was injured in police custody a week earlier.

So far, at least 20 officers have been hurt in the clashes. One person was critically injured in a fire, more than 200 adults and 34 juveniles were arrested, and nearly 150 cars were burned, police said.

Renewed national debate

The death of 25-year-old Freddie Gray renewed a national debate on law enforcement and race that was sparked by the killing of unarmed black men by police last year in Ferguson, Missouri; New York and others.

But rioting and looting in a pocket of Baltimore’s west on Monday prompted the governor to declare a state of emergency, deploying the National Guard – the first time in Baltimore since the unrest that followed the assassination of Martin Luther King in 1968.

President Barack Obama said that the group of youth who stole from businesses and burned buildings and cars should be treated as criminals.

He condemned the group for the “counterproductive” riots, but stressed the need for soul searching in the country.

Demonstrators threw bottles at police and picked up the canisters and hurled them back at officers. But the crowd rapidly dispersed and was down to just a few dozen people within minutes.

Gray was arrested April 12 after running away at the sight of police, authorities said. He was held down, handcuffed and loaded into a police van. Leg cuffs were put on him when he became irate inside. He died a week later after incurring a spinal injury.

Authorities said they are still investigating how and when he suffered the spinal injury – during the arrest or while he was in the van, where authorities say he was riding without being belted in, a violation of department policy.

Six officers have been suspended with pay in the meantime. Al Jazeera