CHICAGO (CBS) — A shooting on the Dan Ryan Expressway early Friday left at least two people wounded, and a third person might have been struck by a stray bullet.

Illinois State Police said troopers responded to reports of a vehicle being shot in the southbound express lanes near 43rd street around 1 a.m. A witness told police someone in a white SUV fired shots at another vehicle after a “traffic altercation.”

Two men were wounded in the shooting. They exited at Garfield Boulevard, where they flagged down Chicago police officers. One of the victims had been shot in the stomach, the other had been shot in the hand, police said. They were taken to Stroger Hospital, police said.

Illinois State Police shut down the southbound express lanes between 26th and 35th streets until about 4:30 a.m. as they searched for evidence.

A short time after the shooting was reported, a third man who might have been wounded in the shooting showed up at Mercy Hospital with a gunshot wound to the leg.

Police said that man told police he had been shot on the expressway, but investigators have not determined if he was involved.

Illinois State Police said it was the 28th expressway shooting in the Chicago area this year.

Willie Butler said Illinois state troopers should always be patrolling the Dan Ryan.

“Have a patrol car patrol that section – from 95th to 22nd Street – constantly. If anything happens, they can pick it up right away,” he said.

Police said the shooting is under investigation. Anyone with information on the incident should call Illinois State Police at 847-294-4400. Callers can remain anonymous.