Police are responding to reports of a shooting at a July Fourth parade in a Chicago suburb, with witnesses describing seeing bloodied bodies covered with blankets.
According to The Chicago Sun-Times, the parade was stopped after just 10 minutes when shots were fired.
Several witnesses told the newspaper that they heard gunfire just after 10am and that hundreds of parade-goers - some visibly bloodied - fled the route, leaving behind chairs, pushchairs and blankets.
A Sun-Times reporter saw blankets placed over three bloodied bodies.
Police told people: "It is not safe to be here."
Debbie Glickman, a Highland Park resident, told Associated Press she was on a parade float with co-workers when she saw people running away from the area.
"People started saying 'there's a shooter, there's a shooter, there a shooter'.
"So we just ran. We just ran. It's like mass chaos down there."
City leaders said on Twitter: "Police are responding to an incident in downtown Highland Park. Fourth Fest has been cancelled. Please avoid downtown Highland Park. More information will be shared as it becomes available."