The New York Police Department decried "packs of youths running as fast as they can" fanning out across the city Monday night and looting stores.
A NYPD spokesperson told NBC News that about 700 arrests were made as a result of protests, looting, and the smashing of windows and destruction of property Monday night.
The commercial Midtown and Union Square neighborhoods in Manhattan and working-class Fordham Road in the Bronx were hit particularly hard late Monday and early Tuesday in ongoing civil unrest following last week's death of George Floyd in Minneapolis. The Upper East Side also saw looting of some high-end stores Monday night.
In the hours leading up to and past Monday's 11 p.m. curfew, announced by Mayor Bill de Blasio, roving groups of people lit street fires, smashed windows, and looted stores, police said.
"There are packs of youths running as fast as they can, smashing windows as fast as they can, and police are trying to catch them as soon as possible," an NYPD spokesperson told NBC News.
There had been peaceful protests in Midtown Manhattan before a handful of people broke off near 30 Rockefeller Plaza and smashed windows at the Nintendo and Michael Kors stores.
Vandals were later seen tearing off protective plywood and metal gates to loot Macy's, Best Buy, Foot Looker and Duane Reade stores in Manhattan.
High-end merchants Longchamp, Chanel and Hermes were also targeted by looters on the Upper East Side.
And several stores along Fordham Road, a main thoroughfare of the Bronx, were also hit, piling on more misery to neighborhoods already hit hard by the coronavirus pandemic, City Councilman Fernando Cabrera said.
"Fordham Road is the lifeblood of the West Bronx, providing jobs as well as essential goods and services,” Cabrera said. “We are already suffering physically, socially and emotionally from the COVID-19 pandemic. We can’t afford to lose our economic engine."
New York City's curfew will begin even earlier on Tuesday evening. It's set to start at 8 p.m.
The death of Floyd, a black man suspected of passing a suspicious $20 bill at a grocery store in Minneapolis, led to the firing and arrest of Minneapolis police Officer Derek Chauvin and set off protests across the nation.
Floyd was held facedown on the pavement with Chauvin's knee apparently digging into his neck for nearly nine minutes as Floyd pleaded: "I can't breathe."
New York City has also seen peaceful protests on Floyd's death.
Floyd's family has been troubled by the violence that has emerged at some protests in major cities, family attorney Benjamin Crump said.
"Let's take a breath for George," he said. "Take a breath for peace. Let's take a breath for justice, and let's take a breath to heal our country."