By Daniel Bases, Robert MacMillan and Zachary Goelman
NEW YORK (Reuters) - Thousands of demonstrators blocked streets, snarling New York City traffic into early Thursday morning, after a grand jury decided not to charge a white police officer for causing the death of an unarmed black man with a chokehold.
Mostly peaceful protests sprang up on Wednesday evening throughout Manhattan, including at Grand Central Terminal, Times Square and near Rockefeller Center, after the panel opted not to indict the officer, Daniel Pantaleo.
Police reported about 30 arrests by mid-evening, but declined to provide updated figures overnight.
The U.S. Justice Department said it was investigating whether the civil rights of the dead man, 43-year-old father of six Eric Garner, had been violated.
Garner was accused of illegally selling cigarettes on a sidewalk when Pantaleo put him in a chokehold from behind and tackled him with the help of other officers. Police said he had resisted arrest.
The city's medical examiner said police officers had killed Garner by compressing his neck and chest, and ruled the death a homicide, adding that Curtis's asthma and obesity had contributed to his death.
The encounter on Staten Island was captured on a video that spread over the Internet and fueled a debate about how U.S. police use force, particularly against minorities.
The video shows Garner arguing with police, saying, "Please leave me alone," before Pantaleo puts him in a chokehold. With officers holding him down, Garner pleads with them, saying repeatedly, "I can't breathe."
The grand jury's decision poses the biggest challenge yet for New York Mayor Bill de Blasio, who took office in January promising to repair relations between black New Yorkers and the police department.
Last week, the city of St. Louis saw rioting, burning and looting after a grand jury in Missouri declined to prosecute a white policeman who shot dead the unarmed black teenager Michael Brown in the suburb of Ferguson.
By contrast, the New York protests were civil. Police allowed demonstrators to block traffic briefly before coaxing them to move on. Marchers snaked through the streets for hours, chanting and bumping up against throngs of tourists.
One group brought traffic on the West Side Highway along the Hudson River to a standstill. Later, a few hundred demonstrators crossed a bridge into Brooklyn.
In one of several "die-ins", demonstrators lay on the pavement silently about a block from where the Christmas tree lighting ceremony was under way at Rockefeller Center.
U.S. Attorney General Eric Holder told reporters in Washington that the Justice Department, which is already probing the circumstances of the Missouri shooting, would also examine the Garner case, as well as the local inquiry into it.
Chokeholds are prohibited by New York police regulations, but the Patrolmen's Benevolent Association, the municipal police union, said the officers involved in the Garner incident had acted within the law.
Keiha Souley, 35, was driving his taxi cab on Broadway when protesters blocked traffic, and said he did not mind the delay.
"You've got to stand up sometime," he said.
Hundreds of protesters also marched in other cities including Washington D.C. and Oakland, California.
On Staten Island, near the place where Garner was apprehended, black 40-year-old banker Daniel Skelton complained: "A black man's life just don't matter in this country."
Garner's stepfather Benjamin Carr, also at the scene, called for calm. "We don?t want no Fergusons here," he said. "All we want is peace."
Pantaleo expressed his condolences to Garner's family in a statement, saying: "It is never my intention to harm anyone and I feel very bad about the death of Mr. Garner."
But Garner's widow Esaw Garner told a news conference: "There's nothing that him or his prayers or anything else will make me feel any different. No I, don't accept his apologies."
(Additional reporting by Zachary Goelman, Frank McGurty, Jonathan Allen, Mica Rosenberg, Daniel Bases, Robert MacMillan, David Ingram, Ellen Wulfhorst, Andrew Chung and Mimi Dwyer in New York, Roberta Rampton and Aruna Viswanatha in Washington; Writing by Ross Colvin, Dan Burns and Frank McGurty; Editing by Leslie Adler and Ken Wills)