Gunshots rang out Monday at a US National Day parade in an affluent Chicago suburb.
According to unconfirmed first media reports, at least two people are said to have died.
The broadcaster WGN TV referred to police circles.
Accordingly, there were also several injured, a suspect is on the run.
The Lake County Sheriff's Office called for people to avoid the Highland Park area.
According to the Chicago Sun-Times, the shots were fired about 10 minutes after the parade began.
Local television stations reported people running away screaming or seeking cover.
Every year, Americans celebrate Independence Day on July 4th.
The day commemorates the ratification of the Declaration of Independence on July 4, 1776.