A young child was reportedly abandoned at San Francisco's Zoo Monday night, but by whom and why is a mystery.

CBS 5 reports that a man and woman drove up to the northwest corner of the then-closed SF Zoo at 8:30 Monday night, dropped off a 5-year-old kid, then fled.

According to CBS 5, an ambulance was passing through the intersection of Great Highway and Sloat Boulevard at the time of the incident. It stopped to help the child, who did not appear to have suffered any injuries.

Police are now seeking the occupants of the car that the child arrived in. According to CBS 5, "a woman was driving with a man in the passenger’s seat and, possibly, another baby in the backseat."