Baltimore streets previously rocked by riots were eerily quiet early Wednesday as residents obeyed an all-night curfew enforced by 3,000 police and National Guardsmen.

The curfew ended at 5 a.m. ET with no reports of disturbances in the early morning hours. The morning rush was getting underway with traffic flowing on most streets downtown.

The curfew, which went into effect at 10 p.m. Tuesday, got off to a not-so-promising start, however, as about 200 protesters initially ignored the warnings of police officers and the pleas of community activists to disperse.

Some threw water bottles or lay down on the ground. A line of police behind riot shields hurled tear gas canisters and fired pepper balls at the crowd and slowly advanced forward to push it back. Demonstrators 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.

Baltimore's police commissioner Anthony Batts said just before midnight that seven people had been arrested for curfew violations, two for looting and one for disorderly conduct.

"I get reports ... that we do not have a lot of activity or movement throughout the city as a whole, so the curfew is, in fact, working as the mayor had called," Batts said.

It capped a day of high tension but relative peace in Baltimore, as thousands of police officers and National Guardsmen poured into the city to prevent another round of rioting like the one that rocked the city on Monday.

Earlier, a line of self-appointed peacekeepers could be seen pushing back a crowd that had assembled near where a CVS pharmacy was looted Monday and where a line of police had been blocking the street all day.

A local pastor could be heard on a loud speaker urging residents to go home and respect the curfew.

"Let's show the world, because the eyes of the world are on Baltimore right now," he said.

Earlier, Baltimore police spokesman Capt. Eric Kowalczyk said that officers will allow some exceptions to the curfew.

"Our officers have discretion, which means if we see you, and you explain you just got off of an airplane and you're headed home, they have the ability to exercise discretion and they don't have to arrest you," he said.

"This is about preserving the public peace."

'The city has been calm today'

Baltimore's mayor and police commissioner had earlier expressed their hope for a calm night in the city after a day spent cleaning up the rubble and damage leftover from violent riots and looting Monday that left the city in disarray.

Batts said the presence of law enforcement in the city has been boosted by the arrival of state troops, the Maryland National Guard as well as officers from New Jersey, Pennsylvania, the D.C. area and several Maryland counties.

"The numbers are growing to make sure everyone is safe," he said.

Earlier in the evening, musicians, marching bands and cheerleaders tried to lighten the mood after a tense two days. 

"We have a long night ahead of us," said Maryland Gov. Larry Hogan at an earlier press conference.

Hogan said authorities have "a lot of manpower on the streets" to ensure that officers "don't get overwhelmed as happened last night." He said about 1,700 members of the National Guard and 1,000 law enforcement officers would be in place overnight.

Hogan said that so far, people have welcomed the presence of National Guard and state troops on Baltimore streets.

"People are concerned. They want us to restore law and order," he said. "Despite the tension, a lot of people are thanking us for being here."

Orioles bar public from Wednesday's game 

Baltimore spent Tuesday cleaning up after riots that kicked off soon after the funeral of Freddie Gray, a 25-year-old black man who died in Baltimore police custody. Hundreds of volunteers swept the streets of broken glass and other debris and boarded up the windows of looted and burned-out businesses and buildings.

Mayor Stephanie Rawlings-Blake thanked all those who "have spent all day yesterday, all day today trying to figure how we can come together as a city, how we can heal."

She said she was forced to keep public schools closed Tuesday because many teachers had called to say they would not come to work. They will reopen Wednesday.

Many businesses and government offices were closed Tuesday. The Baltimore Orioles cancelled their Tuesday game at Camden Yards and — in what may be a first in baseball's 145-year history — said their Wednesday night game against the White Sox would be closed to the public.

Baltimore after curfew

Police with riot shields were lined shoulder to shoulder around the time curfew went into effect in Baltimore on Tuesday night. (CBC News)

By contrast, the Baltimore Symphony Orchestra announced it would give a free noontime concert Wednesday.

Authorities remained vigilant against the possibility of another outbreak of looting and arson overnight. 

"We're not going to leave the city unprotected," Hogan said earlier in the day during a visit to a West Baltimore intersection where cars were burned and windows smashed the night before.

Commissioner Batts responded to criticism that police had been unprepared for Tuesday's escalation of violence and looting by saying that several hundred officers had been deployed to the area around Mondawmin Mall in West Baltimore where posts on social media had urged demonstrators to gather even before the riots began but had deliberately held back when clashes broke out because those participating were teenagers.

"Do you want people using force against 14-,15-, 16-year-old kids?" he said. "They're old enough to know better. They're old enough to be accountable. But they're still kids."

As firefighters doused smoldering fires around the city, many lamented the damage done by the rioters to their own neighbourhoods.

Hundreds of volunteers helped shopkeepers clean up as helmeted officers blocked a stretch of North Avenue in the neighbourhood where Gray was arrested earlier in this month in a case that has become the latest flashpoint in the national debate over the police use of deadly force against black men.

Hardware stores donated trash bags and brooms, and city workers brought in trucks to haul away mounds of trash and broken glass.

With schools closed, Blanca Tapahuasco brought her three sons, ages two to 8, from another part of the city to help sweep the brick-and-pavement courtyard outside a looted CVS pharmacy.

"We're helping the neighbourhood build back up," she said. "This is an encouragement to them to know the rest of the city is not just looking on and wondering what to do."

CVS store manager Haywood McMorris said the destruction didn't make sense: "We work here, man. This is where we stand, and this is where people actually make a living."

Obama calls for national 'soul searching'

In Washington, U.S. President Barack Obama said there have been too many troubling police interactions with black citizens across American in what he called "a slow-rolling crisis." But he said there was no excuse for rioters to engage in senseless violence.

When individuals get crowbars and start prying open doors to loot, they're not protesting. - U.S. President Barack Obama

Obama said those in Baltimore who stole from businesses and burned buildings and cars should be treated as criminals.

"There's no excuse for the kind of violence that we saw yesterday," Obama said. "It is counterproductive. When individuals get crowbars and start prying open doors to loot, they're not protesting, they're not making a statement. They're stealing."

Baltimore-riot

As it got closer to evening Tuesday, the street protests took on a more festive air, with dancers, musicians and marching bands all joining in. (Matt Rourke/Associated Press)

Obama said rioters distracted from days of peaceful protests focused on legitimate concerns "over the possibility that our laws were not applied evenly in the case of Mr. Gray and that accountability needs to exist."

He said he can't force police departments across the country to retrain their officers, but he can work with them and help pay for body cameras to improve accountability.

Obama said the Gray case should prompt some "soul searching" in America about communities where young men are more likely to end up in jail or dead than completing school. He said solutions should involve early education, criminal justice reform and job training.

15 officers hurt, 250 people arrested

The rioting started in West Baltimore on Monday afternoon — less than two kilometres from where Gray was arrested — and by midnight had spread to East Baltimore and neighbourhoods close to downtown and near the baseball stadium.

Suspect Dies Baltimore

Maryland National Guardsmen patrol near downtown businesses in Baltimore, Tuesday, a day after looting and arson erupted. (Patrick Semansk/Associated Press)

The rioters set police cars and buildings on fire, looted a mall and liquor stores and hurled rocks, bottles and cinderblocks at police in riot gear. Police responded occasionally with pepper spray or cleared the streets by moving in tight formation, shoulder to shoulder.

At least 15 officers were hurt. There were 144 vehicle fires, 15 structure fires and about 250 arrests beginning Monday and into Tuesday.

The same community they say they care about, they're destroying. You can't have it both ways. - Baltimore Mayor Stephanie Rawlings-Blake

"They just outnumbered us and outflanked us," Batts said earlier Tuesday. "We needed to have more resources out there."

The rioting was the worst such violence in the U.S. since the turbulent protests that broke out over the death of Michael Brown, the unarmed black 18-year-old who was shot by a white police officer in Ferguson, Mo., last summer.

"I understand anger, but what we're seeing isn't anger," Rawlings-Blake lamented. "It's disruption of a community. The same community they say they care about, they're destroying. You can't have it both ways."

Officials criticized for delaying response

State and local authorities found themselves responding to questions about whether their initial response had been adequate.

Rawlings-Blake waited hours to ask the governor to declare a state of emergency, and the governor hinted she should have come to him earlier.

Baltimore-riots

A ransacked and looted wig shop a day after rioters laid waste to several businesses in what were already struggling parts of Baltimore. (Shannon Stapleton/Reuters)

"We were all in the command centre in the second floor of the state House in constant communication, and we were trying to get in touch with the mayor for quite some time," Hogan said at a Monday evening news conference. "She finally made that call, and we immediately took action."

Rawlings-Blake said officials initially thought they had gotten the unrest under control.

Maryland National Guard spokesman Lt. Charles Kohler said that about 2,000 members would be deployed through the day and that the force could build to 5,000.

"We are going to be out in massive force, and that just means basically that we are going to be patrolling the streets and out to ensure that we are protecting property," said Maj.-Gen. Linda Singh, adjutant general of the Maryland National Guard.

Also, State police said they were putting out a call for up to 500 additional law enforcement officers from Maryland and as many as 5,000 from around the mid-Atlantic region.

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 of a spinal cord injury a week later.

Suspect Dies Baltimore

Baltimore Mayor Stephanie Rawlings-Blake tours the city Tuesday in the aftermath of Monday's rioting. (Matt Rourke/Associated Press)

Authorities said they are still investigating how and when he suffered the 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. A report into the death is expected Friday, CNN reported.

Six officers have been suspended with pay while the investigation continues.

While they are angry about what happened to Gray, his family said riots are not the answer.

"I think the violence is wrong," Gray's twin sister, Fredericka Gray, said late Monday. "I don't like it at all."

With files from CBC News