Amanda Lee Myers?and David Dishneau

BALTIMORE: Baltimore was a city on edge Tuesday as hundreds of National Guardsmen patrolled the streets against unrest for the first time since 1968, hoping to prevent another outbreak of rioting.

Maryland’s governor said 2,000 guardsmen and 1,000 law officers would be in place overnight to try to head off a repeat of the racially charged violence that erupted Monday in some of the city’s poorest neighborhoods and sent a shudder through all of Baltimore.

“This combined force will not tolerate violence or looting,” Gov. Larry Hogan warned.

In a measure of how tense things were, the city was under a 10 p.m.-to-5 a.m. emergency curfew. All public schools were closed Tuesday but classes and after-school sports and clubs were to take place Wednesday, the district announced.

Mayor Stephanie Rawlings-Blake said schools had no choice but to close Tuesday since many teachers called and said they wouldn’t work the day after the riots.

The streets were largely calm all day and into the evening, with only a few scattered arrests. The real test was expected after dark, when the curfew was set to take effect.

The looting, arson and rock- and bottle-throwing by mostly black rioters broke out just hours after the funeral of Freddie Gray, a 25-year-old black man who suffered a fatal spinal cord injury while in police custody. It was the worst such violence in the U.S. since the unrest that erupted last year over the death of Michael Brown, the unarmed black 18-year-old shot by a white police officer in Ferguson, Mo.

Political leaders and residents called the violence a tragedy for the city and lamented the damage done by the rioters to their own neighborhoods.

“The same community they say they care about, they’re destroying. You can’t have it both ways,” Rawlings-Blake said.

Baltimore police Commissioner Anthony Batts said: “I had officers come up to me and say, ‘I was born and raised in this city. This makes me cry.’?’’

But the rioting also brought out a sense of civic pride and responsibility in many residents, with hundreds of volunteers turning out to sweep the streets of glass and other debris with brooms and trash bags donated by hardware stores.

Blanca Tapahuasco brought her three sons, ages 2 to 8, from another part of the city to help clean up the courtyard outside a looted CVS pharmacy in the hard-hit neighborhood where Gray was arrested.

“We’re helping the neighborhood 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.”

As evening fell, police with riot shields lined up shoulder to shoulder across West North Avenue and kept close watch on a chanting crowd of about 1,000 people at the corner where some of the worst violence took place the night before. The gathering resembled a street festival, with musicians playing in the intersection.

Separately, several hundred demonstrators marched through the streets toward downtown Baltimore as the curfew drew near.

At the White House, President Barack Obama called the deaths of several black men around the country at the hands of police “a slow-rolling crisis.” But he added that there was “no excuse” for the violence in Baltimore, and said the rioters should be treated as criminals.

“They aren’t protesting. They aren’t making a statement. They’re stealing,” Obama said.