Updated: 12/19/10 3:31 p.m.

CHICAGO HEIGHTS, Ill. (CBS) – A man and a woman are being questioned after a woman was slain and two men injured during a shooting outside a sandwich shop in south suburban Chicago Heights early Sunday.

The incident began as a disturbance inside a club in Matteson called Knockouts but “it spilled over to Chicago Heights where the shooting was in the parking lot,” according to Chicago Heights police Sgt. Tom Rogers.

LISTEN: Newsradio 780’s Steve Miller Reports

Police responded at 2:39 a.m. to reports of a shooting in the parking lot of the Big Boy Submarine restaurant at 405 W. 14th St. in Chicago Heights, according to a Chicago Heights police statement.

Responding officers found a female lying unresponsive on the ground. Officers found the woman bleeding from the head, Chicago Heights police Sgt. Joe Petrarca said.

Officers tried to give her medical assistance, but there were no signs of life. She was taken to the Cook County Medical Examiner’s office.

The victim is identified as 26-year-old Marquita Campbell. She was apparently shot and may have suffered other trauma, and was dead on the scene, according to the medical examiner’s office.

Rogers said two men were also shot during the incident. One suffered a gunshot wound to the thigh and was taken to St. James Hospital and Health Centers in Chicago Heights, while the other was shot in the forearm but refused medical attention.

Chicago Heights Police say a man and a woman are in custody and are being questioned about the shooting as of Sunday afternoon.

While investigators have not determined the exact motive, Rogers said they don’t believe it was gang-related, or had anything to do with a romance that soured and the victims were not robbed.

“It seemed to be personal,’’ according to Rogers who could not say why investigators believed that.

It was not immediately known whether the victims had been customers of the sandwich shop, which was open at the time.

No charges have been filed as of 2:45 p.m. according to Rogers, who said no one else is being sought in the attack.

Newsradio 780’s Steve Miller and the Sun-Times Media Wire contributed to this report.

Watch & Listen LIVE