The last words of Eric Garner became the rallying cry for protests that swirled in New York after a grand jury refused to indict a police officer who placed the unarmed black man in a chokehold.
“We can’t breathe,” protesters chanted, in mostly peaceful demonstrations that disrupted traffic across the city.
The grand jury decision came just over a week after another grand jury, in Missouri, decided that a police offer who shot dead another unarmed black man, Michael Brown, should not face charges.
Barack Obama, who has been criticised over his response to unrest in Ferguson, suggested the Garner case had reaffirmed his determination to ensure all Americans are treated equally in the criminal justice system.
“When anybody in this country is not being treated equally under the law, that’s a problem,” the president said during a conference in Washington. “And it is my job as president to help solve it.”
About 200 protesters partially closed the New York’s West Side Highway, before police made several arrests, while other groups descended on various locations in midtown Manhattan, including Grand Central Station and the Lincoln tunnel and Brooklyn bridge, which were both briefly closed.
Protesters had descended on central Manhattan before the annual Rockefeller Center Christmas tree lighting, but were kept away from the ceremony.
Groups then dispersed around the city and continued marching well into the night. Police said about 30 arrests had been made by mid-evening.
Earlier, the attorney general, Eric Holder, announced a federal investigation into the July death. “All lives must be valued,” Holder said. “All lives.”
He added that Garner’s death as well as that of unarmed teenager Brown, who was shot dead by police officer Darren Wilson in Ferguson in August, “have tested the sense of trust between law enforcement and the communities they are charged to serve”.
Holder said he respected the rights of protesters to voice their disappointment but called on them to remain peaceful.
Minutes later, Garner’s family appeared alongside civil rights campaigner the Rev Al Sharpton in Harlem to address the media.
Garner’s widow, Esaw, vowed to continue fighting for justice. “As long as I have breath in my body I will fight the fight,” she said.
Sharpton announced a rally in Washington on 13 December. “It’s time for a national march to deal with a national crisis,” he said. “We are not going away.”
