UPDATED 02/13/12 8:16 a.m.

MARKHAM, Ill. (CBS) — Two men were shot early Monday outside a Markham night club, police said.

The incident occurred at 1 a.m. Monday at 163rd Street and Dixie Highway in Markham in front of the Zone club, at 2024 W. 163rd St., following a disturbance inside, police said.

Someone went to a vehicle, grabbed a handgun and opened fire, authorities said.

Two men – both described as being adults under the age of 21 – were shot, authorities said.

One of the men was shot in the chest and taken in critical condition to Advocate Christ Medical Center in Oak Lawn, according to authorities. He was on life support as of Monday morning.

The second man was shot in the arm and taken to Ingalls Memorial Hospital in Harvey.

Police were searching for a suspect early Monday. Half a dozen witnesses were talking with police, but no one was in custody.

No description of the shooter was available.

The Markham incident comes less than 24 hours after another suburban nightclub shooting. Around 3 a.m. Sunday, a man was shot in the head at the Cadillac Ranch, at 1175 Lake St. in Bartlett, after an argument at the club.

And last weekend in Naperville, schoolteacher Shaun Wild, 24, was stabbed to death after a fight between one of his friends and suspect Daniel Olaska,27.

Olaska is now being held on $3 million bond.

The Sun-Times Media Wire contributed to this report.