Several people injured in shootout outside AutoZone in south Chicago suburb

DOLTON, Ill. (CBS) -- Police shut down several blocks in south suburban Dolton for hours Wednesday after several people were injured in a shootout.

The shootout happened Wednesday morning at the AutoZone auto parts store 1110 Sibley Blvd., at University Avenue.

At one time, there were about 40 evidence markers in the parking of the AutoZone, lot and a trail of evidence leading up to a spot where witnesses say they saw five or six people treated in ambulances.

Witnesses said they heard the commotion as two cars came barreling down Sibley Boulevard. At points, the cars came over the curb and through business parking lots - losing parts and taking out signs, witnesses said.

Witnesses said they heard a quarrel as people stood outside the parked cars, and then gunfire - one shot after another.

"There was a car – a vehicle flying – and it hit another vehicle around the corner, and then they went inside AutoZone and started an argument - and that's when they started the shooting, you know?" said witness Saul Mazon.

Police tape and evidence markers surrounded the area where a car riddled with bullet holes was parked. Multiple bullet holes were seen on the driver's side of the silver sedan.

A black sedan was also a focus of the investigation. CBS 2 called the registered owner of the darker-colored vehicle, who said she is a truck driver working about two and a half hours away in Michigan.

The car owner said she is coming back to find out what happened.

Witnesses said they couldn't believe what they saw.

"I was surprised, you know, something like this – this early, this doesn't happen, you know?" said Mazon. "That's all I've got to say."

Witnesses said they saw police pulling guns from the cars. CBS 2's camera caught the moment they loaded them into evidence bags and took photos of the weapons.

Witnesses also reported seeing five or six people being loaded into ambulances – though AutoZone employees said nobody was hurt inside their building.

Mazon said he saw a couple of people running away from this crime scene. Police did go door to door at the businesses along Sibley Boulevard looking for any surveillance video.

Police late Wednesday were tightlipped, and were not providing any information about their investigation - or the status of the people who were wounded.