Gunfire erupted Monday in a town north of Chicago where an American Independence Day parade was being held, with media reporting multiple casualties.

"We are assisting Highland Park Police after shootings on Parade Road," Lake County Sheriff's Department tweeted.

"The 4th of July party is cancelled, please avoid the center of Highland Park," the Municipality of Highland Park added on its Facebook page.

According to local media, several people were affected but no official source gave an immediate report.

Brad Schneider, who represents the state of Illinois in the lower house of Congress, was in this wealthy city, located on the shores of Lake Michigan, when the shots rang out. "My campaign team and I had just met for the start of the parade when the shooting started," he tweeted after taking cover.