Never bring a baseball bat to a gunfight.... An off-duty Chicago police officer shot and injured a man who hit him with a baseball bat late Saturday night on the city's Northwest Side

CHICAGO -   An off-duty Chicago police officer shot and injured a man who hit him with a baseball bat late Saturday night on the city's Northwest Side.

It happened at about 10:30 p.m. as the off-duty officer walked near Schubert Avenue and Monitor Avenue.

News Affairs released a statement saying the officer saw an "aggressive male holding his waistband area."

The unidentified officer, who is assigned to 19th District, announced he was an officer and then patted down the man.

That man called out to family members. That's when a 32-year-old man came out of a nearby apartment carrying a baseball bat.

The 37-year-old officer again identified himself as a Chicago police officer, but the man walked toward him and hit him multiple times with the bat.

The officer then pulled out his service weapon and fired several shots, hitting the man in the leg and in the abdomen.

The man was taken to Advocate Illinois Masonic Medical Center in critical condition.

The officer was taken in fair condition to Northwestern Memorial Hospital with an injury to his arm. His injuries were considered to be non-life-threatening.

The man whom the officer originally approached for a pat down was taken into custody.

The Independent Police Review Authority, which investigates all police shootings, is investigating the incident.