By Lauren Victory

CHICAGO (CBS) — A 6-month-old boy and a 13-year-old girl were critically injured, and two other people were wounded in a shooting Wednesday night in the South Loop.

Police said five people were in a car heading west on Cermak Road near State Street shortly after 9 p.m., when a man wearing a black ski mask walked up to them and started shooting.

A 6-month-old boy was shot twice in the stomach. He was in critical condition Thursday morning at Lurie Children’s Hospital. A 13-year-old girl was shot in the shoulder, and also was in critical condition at Lurie.

A 37-year-old woman was shot in the knee, and was stabilized at Northwestern Memorial Hospital.

A 27-year-old man suffered a graze wound to his arm, and refused treatment at the scene. Police said they believe he was possibly the target of the attack, and is not cooperating with detectives.

A 15-year-old girl who was in the car was not wounded.

Investigators said the shooting might have started as a car chase about a mile and a half away.

“We do not believe this was a random act. This appears to be, I don’t want to use the term targeted, but it does appear to be some type of interaction between two vehicles,” Chicago Police Deputy Chief Kevin Ryan said.

Detectives were reviewing surveillance footage to figure out exactly what happened.

The victims’ car rolled across State Street after the shooting, coming to a stop in the eastbound lane of Cermak Road.

No one was in custody Thursday morning. Area Central detectives were investigating.