New York was under a curfew that would last until early Tuesday morning, officials said, after looters raided stores in central Manhattan, targeting some of the city's top retailers.
Up market fashion store Michael Kors on Fifth Avenue was among the luxury outlets hit, along with Nike, Lego and electronics shops across Midtown, before the 11pm to 5am curfew came into effect.
Groups of young people moved from block to block around the district, usually bustling with tourists but deserted due to the coronavirus, with entire streets blocked by police.
Images from local NY1 television showed some young people running out of a Best Buy electronics store before being apprehended by the police. Stores in the south of Manhattan suffered a similar fate.
The New York Times reported that the flagship Macy's department store had also been targeted by looters.
Police did not immediately confirm this, simply saying that numerous stores were hit and arrests made in the hundreds across the city.
Mayor Bill de Blasio said a lot of stores around Madison Avenue had been hit and the situation was really not acceptable. As a result, he said, the curfew would start from 8pm on Tuesday instead of 11pm.
The city is fully under control, and overwhelmingly calm and peaceful, he nevertheless insisted on NY1.
The imposition of the curfew had been announced a few hours earlier by the mayor and New York State Governor Andrew Cuomo after protests and looting during the weekend - notably in the trendy SoHo district.
The mayor tweeted late on Monday that protesters were overwhelmingly peaceful today but that some people were out to damage property and steal.
We support peaceful protest in this city. But right now, it's time to go home, Mr de Blasio said.
New York, the economic capital of the United States, and around 40 other cities across some sixteen states of the country have imposed curfews after violent protests against police brutality triggered by the death of George Floyd in Minnesota.