Autopsy results were pending Sunday on the human remains found at a forest preserve near Niles, the Cook County medical examiner's office said.

Forest preserve maintenance workers discovered the skeletal remains early Saturday afternoon at the Bunker Hill Forest Preserve, operated by the Cook County Forest Preserve District and located near the intersection of Touhy and Caldwell avenues.

Cook County Forest Preserve District spokesman Steve Mayberry said in the course of their routine duties, the workers came across a sleeping bag in which the remains were found. Mayberry said Forest Preserve police were notified. Police then contacted the Medical Examiner's office.

Mayberry said it isn't clear whether the badly decomposed skeleton was male or female. It wasn't even clear, he said, whether it was clothed. "It had clearly been decomposing for quite a while. I couldn't characterize it as a complete skeleton," he said.

Mayberry said the investigation will be considered open until police are contacted by the medical examiner's office.