Police Superintendent David Brown described the events and damage caused in the Magnificent Mile shopping district and other parts of the city as “an incident of pure criminality” and said it was not an organised protest.
At one point, shots were fired at police and officers returned fire. Mr Brown says a heavy police presence is expected in the city centre until further notice.
Those arrested were expected to face charges including looting, disorderly conduct and battery against police.
Chicago mayor Lori Lightfoot said the city has activated a neighbourhood protection programme that will be in place “for foreseeable days until we know our neighbourhoods are safe”.
Anti-police graffiti was seen in the area of the shopping district, which is one of Chicago’s most-visited tourist attractions. Hours earlier, dozens of people had faced off with police after officers shot and wounded a person on Sunday in the city’s Englewood neighbourhood, about 10 miles away.
Along the Magnificent Mile, people were seen going in and out of stores carrying shopping bags full of merchandise as well as at a bank, the Chicago Tribune reported, and as the crowd grew vehicles dropped off more people in the area. On streets throughout the city centre area, empty tills from stores were strewn about and cash machines were ripped open.
UPDATE: Mayor Lightfoot joins CPD Superintendent Brown to provide update on overnight criminal activity. https://t.co/snFh5haaCZ
— Chicago Police (@Chicago_Police) August 10, 2020
Stores miles from the city centre were also ransacked, with car parks littered with glass and items from inside the stores.
One officer was seen slumped against a building, several arrests were made and a rock was thrown at a police vehicle, the newspaper said.
Train and bus services were temporarily suspended at the request of public safety officials, the Chicago Transit Authority said on Twitter.
Chicago and its suburbs, like many other cities, saw unrest following the death of George Floyd on May 25 in Minneapolis. Chicago’s central business district and its commercial areas were shut down for several days after violence erupted and stores were damaged in the wake of marches protesting Mr Floyd’s death.
Mr Floyd, a black man who was handcuffed, died after a white officer pressed his knee against Mr Floyd’s neck for nearly eight minutes as Mr Floyd said he could not breathe.
In the shooting on Sunday in Englewood, police said in a statement that they responded at about 2.30pm to a call about a person with a gun and tried to confront someone matching his description in an alley. He fled from officers on foot and shot at officers, police said.
Officers returned fire, wounding him, and a gun was recovered, police said. He was taken to a hospital for treatment and three officers involved also were taken to a hospital for observation, the statement said.
More than an hour after the shooting, police and witnesses said a crowd faced off with police after someone reportedly told people that police had shot and wounded a child. That crowd eventually dispersed.
