Police say around 4:40 p.m. at the Country Lakes Park, 736 Genesee Drive, the boy -- approximately 7-10 years old with blonde hair, wearing a gray sweatshirt with red sleeves -- was seen in the company of a male adult. The adult was described as approximately 6' tall and 200 pounds, wearing a dark knee-length coat, dark pants, black hat and gloves.
The boy may have been riding a Mongoose bike at the time, which was left on the scene.
The pair was last seen walking south.
Officers are re-interviewing witnesses and alerting area schools after a six-hour search which turned up nothing unusual.
There are no reports of missing children in the Naperville-Aurora area. Anyone with information is asked to call police.