The Rockford Register Star reports (http://bit.ly/1dgK1nX ) the incident occurred around 3 a.m. Saturday.
Police said there was no evidence that cars, buildings or other objects had been hit.
Officers also responded to another report of shots fired around 12:15 a.m. on Saturday.
Witnesses told police it appeared people inside two vehicles were shooting at each other as they drove through the neighborhood.
Information from: Rockford Register Star, http://www.rrstar.com