CHICAGO - WARNING: VIDEOS IN THIS STORY CONTAIN GRAPHIC LANGUAGE
Twitter users have posted videos of hundreds of people looting stores such as Nordstrom, Walgreens, Macy's, Coach, Gucci and Louis Vuitton.
The Chicago Tribune reported that it observed people carrying shopping bags full of merchandise in the areas where the looting was happening and at least one U-Haul van was seen pulling up.
An Apple store and Tesla dealership were among those targeted.
In one video, a woman seen carrying bags appears to have been taken into custody after tripping while running away from police.
Other videos show apparent arrests happening, but the circumstances are unclear.
Officials told the Chicago Tribune that one gun was seized in connection with the looting. A rock also reportedly was thrown at a police car while anti-cop graffiti was spotted in two locations.
The looting began around midnight but appeared to be mostly under control by 3 a.m. local time, reports say.
Yet around 5:45 a.m. this morning, some stores were still being targeted.