Thousands of people rallied late Monday in U.S. cities including Los Angeles and New York to passionately but peacefully protest a grand jury's decision not to indict a white police officer who killed a black 18-year-old in Ferguson, Missouri.

They led marches, waved signs and shouted chants of "hands up, don't shoot," the refrain that has become a rallying cry in protests over police killings across the country.

The most disruptive demonstrations were in St. Louis and Oakland, California, where protesters flooded the lanes of freeways, milling about stopped cars with their hands raised in the air.

Activists had been planning to protest even before the nighttime announcement that Officer Darren Wilson will not be charged in the shooting death of Michael Brown.

The racially charged case in Ferguson has inflamed tensions and reignited debates over police-community relations even in cities hundreds of miles from the predominantly black St. Louis suburb. For many staging protests Monday, the shooting was personal, calling to mind other galvanizing encounters with local law enforcement.

Police departments in several major cities braced for large demonstrations with the potential for the kind of violence that marred nightly protests in Ferguson after Brown's killing. Demonstrators there vandalized police cars and buildings, hugged barricades and taunted officers with expletives Monday night while police fired smoke canisters and tear gas. Gunshots were heard on the streets and fires raged.

But police elsewhere reported that gatherings were mostly peaceful following Monday's announcement.

As the night wore on, dozens of protesters in Oakland got around police and blocked traffic on Interstate 580. Officers in cars and on motorcycles were able to corral the protesters and cleared the highway in one area, but another group soon entered the traffic lanes a short distance away. Police didn't immediately report any arrests.

A diverse crowd of several hundred protesters marched and chanted in St. Louis not far from the site of another police shooting, shutting down Interstate 44 for a time. A few cars got stuck in the midst of the protesters, who appeared to be leaving the vehicles alone. They chanted "hands up, don't shoot" and "black lives matter."

"There's clearly a license for violence against minorities, specifically blacks," said Mike Arnold, 38, a teacher. "It happens all the time. Something's got to be done about it. Hopefully this will be a turning point."

In Seattle, marching demonstrators stopped periodically to sit or lie down in city intersections, blocking traffic before moving on, as dozens of police officers watched. After hours of marching peacefully, protesters also hurled canned food, bottles and rocks, police said. Five people were arrested.

Groups ranging from a few dozen to a few hundred people also gathered in Chicago, Salt Lake City, and Washington, D.C., where people held up signs and chanted "justice for Michael Brown" outside the White House.

"Mike Brown is an emblem (of a movement). This country is at its boiling point," said Ethan Jury, a protester in Philadelphia, where hundreds marched downtown with a contingent of police nearby. "How many people need to die? How many black people need to die?"

In New York, the family of Eric Garner, a Staten Island man killed by a police chokehold earlier this year, joined the Rev. Al Sharpton at a speech in Harlem lamenting the grand jury's decision. Later, several hundred people who had gathered in Manhattan's Union Square marched peacefully to Times Square.

In Los Angeles, which was rocked by riots in 1992 after the acquittal of police officers in the videotaped beating of Rodney King, police officers were told to remain on duty until released by their supervisors. About 100 people gathered in Leimert Park, and a group of religious leaders held a small news conference demanding changes in police policies.

A group of about 200 demonstrators marched toward downtown.

The marchers briefly shut down the northbound and southbound lanes of Interstate 110 in downtown Los Angeles late Monday night, according to City News Service. People stood and lay in the northbound lanes and the center divider. California Highway Patrol officers declared an unlawful assembly.

After midnight, about 100 police officers wearing riot gear fired hard foam projectiles into the ground to disperse about 50 protesters on Pico Boulevard in downtown Los Angeles, the Los Angeles Times reported.

Another splinter group of about 30 people marched all the way to Beverly Hills, where they lay down in an intersection.

Chris Manor, with Utah Against Police Brutality, helped organize an event in Salt Lake City that attracted about 35 people.

"There are things that have affected us locally, but at the same time, it's important to show solidarity with people in other cities who are facing the very same thing that we're facing," Manor said.

At Cleveland's Public Square, at least a dozen protesters' signs referenced police shootings that have shaken the community there, including Saturday's fatal shooting of 12-year-old Tamir Rice, who had a fake gun at a Cleveland playground when officers confronted him.

In Denver, where a civil jury last month found deputies used excessive force in the death of a homeless street preacher, clergy gathered at a church to discuss the decision, and dozens of people rallied in a downtown park with a moment of silence.