Multiple people were shot overnight at a Juneteenth celebration in Willowbrook, Illinois, police say.

Ten patients were transported to four hospitals with injuries ranging from graze wounds to more serious gunshot wounds, according to Joe Ostrander, battalion chief of the Tri-State Fire Protection District. Two of those patients are in critical condition.

At least 12 ambulances responded to the scene, Ostrander added.

Witnesses say the shooting took place around 12:30 a.m. in a parking lot in Willowbrook, about 21 miles west of Chicago.

CNN has reached out to the sheriff's office for more information on the shooting.