Chicago police detectives are questioning a person after an off-duty officer was shot in the leg during what the department says was an attempted robbery.

Interim Police Superintendent John Escalante says the person being questioned arrived at an area hospital with a gunshot wound. He says the officer told detectives that he believes he shot one of the suspects who tried to rob him early Monday on the city's South Side. Police say the shooting occurred about 2:20 a.m.

The officer was parked near his home when two gunmen approached his car and announced a robbery. He was not in uniform.

Escalante says the officer was "trying to comply" with the robbers' demands but pulled his weapon and fired when one of the robbers told the other to shoot him.