Chicago police are asking for the public's help in the search for at least two gunmen who ambushed an off-duty officer and shot him in the abdomen as he sat in his Jeep in the city's Calumet Heights neighborhood Monday.

The officer was stopped at a traffic light while off-duty in his personal vehicle at about 12:21 p.m. when the suspects pulled up behind and alongside the vehicle and fired shots inside, wounding the officer in the lower torso, Chicago Police Superintendent David Brown said.

Shotspotter alerted tactical teams who responded to the scene and transported the officer to the University of Chicago Medical Center, ABC 7 reports.

Doctors said the 32-year-old officer underwent surgery Monday afternoon and remains in fair condition.

The reason for the attack is unknown.

"We heard some rumors about a carjacking. We don't know at this point," Brown said. "Circumstances suggest several different narratives of what this might be, could be a misidentification, and it could be road rage, could be carjacking. We just don't know, it's too early to tell given the circumstances."

While the motive is unclear, CPD asked for the public's help in finding information Monday night.