It happened just after midnight Saturday in the 100 block of N. Wabash, police said.
The victims were inside of the Taco Bell when a male suspect fired shots into the restaurant, said police.
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A 31-year-old man was shot in the leg and transported to Northwestern Hospital in good condition, according to police.
A 40-year-old man suffered a gunshot wound to the left shoulder. He was also taken to Northwestern Hospital where he was last listed in good contion.
Investigators said it's unclear what led to the shooting.
The incident is being investigated by Area Three detectives.