Many protesters defied the curfew, and the police made dozens of arrests.
As a citywide curfew fell on New York Wednesday for a third night, large numbers of protesters flouted the requirement that they clear the streets by 8 p.m.
Defiance of the curfew had increased since Tuesday, when several large groups continued to demonstrate long past the deadline.
The crowds in Brooklyn and Manhattan who were demonstrating against police brutality and systemic racism on Wednesday were bigger. And the police were quicker to enforce the clampdown than they had been before, moving swiftly to disperse demonstrators from rainy city streets and to arrest those who failed to clear out.
In Downtown Brooklyn, officers hemmed in demonstrators on Cadman Plaza, then charged at them with seemingly little provocation, according to New York Times reporters at the scene.
In Manhattan’s East Midtown area, officers shoved protesters onto sidewalks and arrested those who would not disperse.
Terence A. Monahan, the Police Department’s chief of department, explained the tough approach while speaking to reporters in Midtown.
“When we have these big crowds, especially in this area, especially where we’ve had the looting, no more tolerance,” he said. “They have to be off the street. An 8 o’clock curfew — we gave them to 9 o’clock. And there was no indication that they were going to leave these streets.”
Mayor Bill de Blasio, in a radio interview on WBLS just after 8:30 p.m. as the police were beginning to make dozens of arrests, said the curfew appeared to be having “a calming impact” and was “allowing things to get back to a better place.”
“There is protest out there,” he said, “but it is consistently peaceful.”
Later on Wednesday, after the police had made most of the arrests across the city, Mr. de Blasio called into MSNBC for an interview, but he was not asked about the police department’s enforcement of curfew and he did not discuss it.
A police spokesman said that officers had made an unspecified number of arrests after the curfew began but declined to provide further details.
The police’s approach appeared to be even more robust that the one they employed on Tuesday, when they managed to tamp down the kind of looting and vandalism that broke out in Manhattan and parts of the Bronx on Sunday and Monday.
As of 9:30 p.m., Chief Monahan said, no looting had been reported in the city.
Not all of the protesters were met with the same show of force. Two large groups marched in largely residential neighborhoods of Brooklyn until about 11 p.m. The police broke up the bigger group soon after that, making several arrests.
Riot police descend on a crowd in Brooklyn.
For more than two hours on Wednesday night, hundreds of protesters marched through Downtown Brooklyn peacefully, with cyclists helping to direct traffic and organizers calming anyone who tried to confront the police.
The group stopped at courthouses and chanted for justice, altering their path to avoid a direct confrontations with officers who could be seen in the distance blocking access to the Manhattan Bridge.
It was 8:45 p.m., almost an hour past curfew, when the group marched to…