CHICAGO (CBS) – Illinois State Police are investigating an expressway shooting that happened early Sunday morning.

District Chicago troopers responded to the shooting around 2:57 a.m. on I-55 southbound near California Avenue.

No injuries were reported.

The ramp from California Avenue to I-55 southbound was closed for investigation. All lanes reopened around 6 a.m. 

Additional information about the incident was not immediately available.

Anyone who witnessed the shooting or has any knowledge of the shooting is asked to contact ISP by phone at 847-294-4400, or email at ISP.CrimeTips@Illinois.gov.

Witnesses can remain anonymous.