New York's public schools will close temporarily in the wake of the rise in coronavirus cases, Mayor Bill de Blasio announced on Wednesday.
The schools will shut from Thursday "out an abundance of caution" after the city recorded a seven-day average positivity rate of three percent, said de Blasio, according to AFP.
"We must fight back the second wave of COVID-19," he wrote on Twitter.
The three percent threshold had been agreed between the city government and teaching unions when New York's schools began reopening in September.
New York City is the largest school district in the United States with 1.1 million students. It has been the only major city in the United States to commit to offering in-person classes this fall as part of a hybrid system that included online learning.
De Blasio's announcement will see hundreds of thousands of children return to remote learning. He had warned of an imminent closure since the end of last week.
Meanwhile on Wednesday, the United States recorded a quarter-million COVID-19 deaths, the latest NBC News numbers showed.
The death rate has been accelerating in recent weeks as cases have been surging across the country.
The 250,000th death was logged Wednesday morning, the data revealed.
In the last four weeks there has been a 42 percent increase in the number of fatalities, from a weekly average of 821 per day in early October to last week’s average of 1,167 per day, according to an NBC News analysis of the available data.