NEW YORK — A day that began with hope that New York City was beginning to find a way out of the crisis caused by the coronavirus and a week of angry demonstrations over police brutality ended Wednesday with more violence.

Peaceful protests over the death of George Floyd drew thousands of people, but were broken up by police as rain poured down about an hour after the city's 8 p.m. curfew went into effect. 

Then, with the streets quiet for the first time in days, police said a man ambushed officers on an anti-looting patrol in Brooklyn, stabbing him in the neck. The attacker was shot by responding officers and was in critical condition.

Two officers suffered gunshot wounds to their hands in the chaos, but all three wounded officers were expected to recover.

Police Commissioner Dermot Shea called it "a completely, cowardly, despicable, unprovoked attack on a defenseless police officer." While he declined to say what motivated the attack, he drew a line to the heated rhetoric of the past week, in which angry crowds decrying police violence have also hurled insults, and sometimes bottles, bricks and firebombs, at officers and their vehicles.

"Words matter," Shea said.

More protests were planned for Thursday around New York, and Gov. Andrew Cuomo called for a statewide moment of silence at 2 p.m., to coincide with a memorial service in Minnesota for Floyd.

Wednesday night's attack came at the end of the day in which the police had drawn praise for bringing a stop to days of pilfering and destruction in some parts of the city, but also harsh criticism for rough tactics used to enforce the city's curfew.

About an hour after the 8 p.m. deadline to get off the street, officers began moving in on crowds of demonstrators in Manhattan and Brooklyn, at times blasting people with pepper spray or using batons to shove people who didn't move fast enough.

(AP Photo/Frank Franklin II)

Asked whether those officers had acted appropriately, de Blasio said Thursday that he had not seen videos of officers using batons on peaceful protesters. He added, " if there's anything that needs to be reviewed."

The mayor said protesters should observe the curfew that's in place through Sunday. "If at a certain point, officers say, 'It's time, people need to go now,' people need to listen to that," he said.

NYPD Chief of Department Terence Monahan said about 60 people were arrested near Central Park for defying an order to go home. 

"When we have these big crowds, especially in this area, especially where we've had the looting, no more tolerance," Monahan said. "They have to be off the street."

City Public Advocate Jumaane Williams, who attended a rally in downtown Brooklyn, expressed outrage that police had broken up the peaceful demonstration by shoving protesters and hitting them with batons.

"I can't believe what I just witnessed & experienced," Williams wrote on Twitter. He called the use of force on nonviolent protesters "disgusting." 

New York City police officers arrest protesters following a rally calling for justice over the death of George Floyd, Wednesday, June 3, 2020, in the Brooklyn borough of New York. (AP Photo/Frank Franklin II)

As the evening deepened, there were few reports of the mayhem that had occurred on several days of demonstrations, when protesters burned police vehicles and showered officers with debris. Gone also were the roving bands of people who smashed their way into scores of stores and stole merchandise Sunday and Monday nights.

During the day, some protesters had been heartened by news that three more Minneapolis police officers had been charged in connection to the May 25 death of Floyd, a black man who died after an officer pressed a knee on his neck. 

But most said they wanted bigger societal changes to fight institutional racism in policing.

"There's been progress, but are we at a point where we can all celebrate? No," said demonstrator Lisa Horton, calling for "radical change" in the criminal justice system.

Tuesday night's protests had also been mostly peaceful, prompting de Blasio to declare that an early curfew was working.

It is set to remain in effect through at least Sunday, with the city planning to lift it at the same time it enters the first phase of reopening after more than two months of shutdowns because of the coronavirus.