Large crowds clashed with police as rioters vandalized stores in downtown Chicago overnight Sunday, with officers returning fire after being targeted by gunfire, police said.
Local media cited police saying more than 100 people were arrested and 13 officers wounded as rioters smashed windows and looted high-end stores.
"Shots fired at police who returned fire," tweeted Chicago police spokesman Tom Ahern early on Monday, who indicated that no officers had been injured in that exchange.
Local media said law enforcement was unsure what had sparked the unrest, which came after a reported police shooting in the city's Englewood neighborhood.
Debris could be seen littering a parking lot outside a damaged Best Buy where people loaded merchandise into cars, while an Apple store had its window smashed.
The Chicago Transit Authority suspended all train and bus service to the downtown area at the request of public safety officials. Bridges that lead into the city were also raised to limit access.
Protests over racism and police killings have erupted across the United States in recent months, ignited by the May 25 death in Min