Protesters demonstrate in Times Square after the grand jury's decision to not charge Ferguson police officer Darren Wilson in the shooting death of unarmed 18-year-old Michael Brown was announced, in New York November 24, 2014. [Photo/Agencies]

Thousands of people rallied late Monday in US 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 an unarmed black 18-year-old in Ferguson, Missouri.

They led marches, waved signs and shouted chants of "Hands Up! Don't Shoot,'' the slogan that has become a rallying cry in protests over police killings across the country.

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 said they were bracing 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, hugged barricades and taunted officers with expletives Monday night while police fired smoke canisters and pepper spray. Gunshots were heard on the streets.

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

About 100 people holding signs that read "The People Say Guilty!'' blocked an intersection in downtown Oakland, California, after a line of police officers stopped them from getting on a highway on-ramp. Minutes earlier, some of the protesters lay on the ground while others outlined their bodies in chalk. A similar scene unfolded in Seattle as dozens of police officers watched.

Several hundred people marched through downtown Philadelphia with a large contingent of police nearby.

"Mike Brown is an emblem (of a movement). This country is at its boiling point,'' said Ethan Jury, a protester in Philadelphia. "How many people need to die? How many black people need to die?''

Several hundred people who had gathered in Manhattan's Union Square to watch the announcement marched peacefully to Times Square after the family of Eric Garner, a Staten Island man killed by a police chokehold earlier this year, joined actvist Rev. Al Sharpton at a speech lamenting the grand jury's decision.

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 while others held a small news conference demanding changes in police policies.

A splinter group of about 30 people broke away and marched through surrounding streets, blocking intersections, but the demonstrations remained mostly small and peaceful.

At Cleveland's Public Square, at least a dozen protesters held signs Monday afternoon and chanted "Hands up, don't shoot,'' which has become a rallying cry since the Ferguson shooting. Their 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.