Thousands of protesters hit the streets of New York after a grand jury declined on Wednesday to charge a white police officer in the choking death of a black man, days after a similar decision sparked unrest in US cities.
Soon after the decision by the grand jury, hundreds of protesters converged on Rockefeller Center and in New York City's iconic Times Square chanting "No justice, no peace," the rallying cry of demonstrators already angered by a separate grand jury decision last week not to indict a white policeman in the fatal shooting of black teenager Michael Brown in Ferguson, Missouri.
Police made at least 30 arrests, New York Police Commissioner Bill Bratton said.
A series of small protests converged into a march of about 5,000 people down Broadway and eventually into Times Square, the Washington Post reported. Drivers stuck in traffic by the march honked their horns in solidarity, the paper said.
Both cases, coupled with the death of a 12-year-old black boy who was gunned down by police officers in Ohio while handling a toy pistol in a playground, have reignited a longstanding debate in the United States about relations between law enforcement and African-Americans, as well as accusations of overly aggressive policing.
Following Wednesday's jury decision, attorney general Eric Holder said the US justice department will launch a federal civil rights investigation into the case of Eric Garner, 43, who died after being placed in a chokehold by New York police officer Daniel Pantaleo while being arrested on suspicion of selling untaxed cigarettes on Staten Island, a NYC borough.
An amateur video of the arrest shows Garner, a heavy set man who suffered from asthma and had six children, gasping "I can't breathe, I can't breathe" as police officers held him to the ground with his throat constricted.
Holder's announcement means Pantaleo could still face trial.
Protesters in Times Square waved signs with messages such as "Black lives matter," and "Respect human lives."
There was another protest at Grand Central Terminal, where about 50 protesters lay, pretending to be dead, and on Staten Island, where Garner's clash with police happened.
Small demonstrations also broke out in Harlem, Union Square and Columbus Circle, while there were similarly small but peaceful protests in Washington, DC.
In New York, demonstrator Susan Schneider told AFP: "The police has impunity. They can run away whatever they do.
"And when you see them on the streets, how they are equipped, it's like war. It's worse than in the 60s. The racism is more strong now."
Video: Protests in New York as cop cleared
'An American problem'
The July death of Garner is one of a string of high-profile, racially charged incidents in which white police officers have been accused of using unreasonable force or being too quick to fire at black suspects.
Garner's widow, Esaw Garner, said she rejected Pantaleo's apology.
"Hell, no," Garner said, according to the New York Times. "The time for remorse for the death of my husband was when he was yelling to breathe."
"He's still feeding his kids," Garner said, "and my husband is six feet under and I'm looking for a way to feed my kids now."
In brief comments following the grand jury decision, Barack Obama - the first black president of the US - addressed the inherent mistrust many African Americans have of police.
"We're seeing too many instances where people do not have confidence that folks are being treated fairly," Obama said.
"In some cases, those may be misperceptions, but in some cases that's a reality, and it is incumbent upon all of us as Americans... that we recognize this is an American problem and not just a black problem or a brown problem."
The August shooting death of 18-year-old Brown by a white policeman in Ferguson sparked consecutive nights of violence and became a rallying cry for African-American communities across the United States fed up with what they say is racially biased policing.
A grand jury in that case also decided not to charge the white officer involved, triggering demonstrations in cities across America last week and into the weekend.
Wearable cameras for cops
A New York City medical examiner had ruled Garner's death a homicide caused in part by the chokehold used during the arrest.
Mayor De Blasio has said authorities need to address the "underlying reality" highlighted by the deaths of Brown and Garner.
De Blasio, who is white, has a mixed-race son and said he is well aware of the difficulties young black people can face.
"We've had to literally train him, as families have all over this city for decades, in how to take special care in any encounter he has with the police," the mayor said.
De Blasio noted that America is "dealing with centuries of racism."
New York authorities announced a pilot program to equip about three dozen police officers with body cameras to record their behaviour towards the public.
De Blasio hailed the tool as "one of the ways to create a real sense of transparency and accountability."
Video: Eric Garner's family asks for peace as protests erupt