UPDATE: 11.50 p.m. EST – Chicago Police Department Superintendent Eddie Johnson said two suspects were involved in a robbery at a bank in Des Plaines. While one of them was taken into custody at the scene, the other suspect escaped and stole a car. This resulted in a police chase.

The Chicago Police Department officers were waiting for the suspect when he exited the Kennedy Expressway at the Old Irving Park road. Upon seeing the police, the suspect opened fire during which the officer was shot. The suspect then got off the vehicle and entered a music store where he exchanged gunfire with a Des Plaines police officer. During the gun battle, a 15-year-old, who was at the store, was shot in the stomach. The 32-year-old suspect too was killed in the incident. Johnson said the 46-year-old CPD officer who was injured in the incident was a 17-year veteran of the Chicago police and had received over 100 awards.

Original story:

At least three people including a police officer were in critical condition following a gun battle in Chicago's Old Irving Park neighborhood Tuesday night.

Chicago police spokesman Anthony Guglielmi said a bank robbery led to a police chase which ended in a crash. Following the crash, the police and the suspect involved in the bank robbery engaged in a “gun battle” during which the officer was shot in the head and transported to Illinois Masonic Hospital.

Though the spokesman initially tweeted that the “officer suffered a graze wound to the head,” he later confirmed that “Imaging reveals the bullet did penetrate and exit the officers skull. Injuries are more serious than preliminary diagnosis.”

During the incident, two others, including a 15-year-old boy, were also shot. They were receiving treatment and were said to be in critical condition. It was, however, not clear how the two victims suffered injuries.

Speaking to ABC 7 Chicago, witnesses said police were chasing a car, which they eventually rammed into. The driver then got out of the vehicle and began shooting. He then ran into a music store and the shooting continued.

In a statement, Chicago Mayor Lori Lightfoot said, "Tonight, our hearts are breaking as we're reminded of the service and sacrifice our officers make every day to protect us and keep our communities safe. We're monitoring the situation, and Amy and I are asking all Chicagoans to pray for the CPD officer who was shot this evening.”

Meanwhile, investigation was ongoing and details regarding the robbery as well as the suspect were not available.

Chicago Police In this photo, a Chicago police badge hangs in front of the City of Chicago Public Safety Headquarters in Chicago, Dec. 1, 2015. Photo: Getty Images/ Scott Olson