Thousands of people marched in Manhattan Saturday to protest the killing of unarmed black men by police officers - a demonstration marred by sporadic clashes with police.
Two officers were assaulted by protesters and hospitalized, police said. Information about their injuries was not available.
The march was part of a day of protests across the nation to accompany the "Justice for All" march on the Capitol in Washington.
Protesters streamed onto Brooklyn Bridge Saturday night, closing traffic in both directions for nearly an hour. Debris, including a trash can, was thrown from the bridge's walkway at police officers escorting protesters on the roadway below, police said.
One person was arrested at the bridge on a charge of disorderly conduct, said police. No details of the arrest were available.
Officers found a bag containing hammers and a black mask during the protest.
The windows of one squad car were smashed by protesters, police said.
Mayor Bill de Blasio condemned the "ugly and unacceptable" violence.
"We will not allow a small contingent of agitators to bring disorder and violence to these protests," he said. "Those who reject peaceful protest and provoke violence can expect immediate arrest and prosecution.
The "Millions March" route began at Washington Square Park and headed north to Herald Square, before turning south to 1 Police Plaza.
Demonstrators set off fireworks at the bridge and at a location on Madison Avenue.
The march swelled to at least 25,000 people, police said.
Protesters carried signs reading "Jail Killer Cops" and "Black Lives Matter." They chanted "I can't breathe," the last words of Eric Garner, who died after being placed in a police chokehold while being arrested on Staten Island.
Family members of people killed by New York City police over decades were among the demonstrators. They included Iris Baez, whose son Anthony Baez died after apparently being placed in a police chokehold in 1994, and Donna Carter, whose teenage son was shot and killed by police in the 1990s while carrying a toy gun."
"It's good to see people of all colors here to say enough is enough," Carter said. "I'm a parent and every child that's killed feels like my child."
Others were there to show their outrage, including Rich Alexandro, 47, who carried a handmade sign with dozens of names of victims of police killings in which officers were never charged.
"It just seems like the cops are Teflon," Alexandro said. "There's no justice."
In Washington, the march included Garner's family and that of Michael Brown, the 18-year-old killed by a police officer in Ferguson, Missouri.
Organizers have said the demonstrators are calling on Congress to hold hearings and pass legislation improving the state grand juries that choose whether or not to indict police officers who kill civilians.