The body of a three-year-old girl who was the subject of an Amber Alert (search) was found Sunday about four miles from her home in this small Will County community, officials said.

Wilmington Police Chief James Metta said a pair of hikers found the body of Riley Fox (search) in a section of Forked Creek that runs through Forsythe Woods.

Between 500 and 600 volunteers had been searching for the girl, Metta said.

Riley's father, Kevin Fox, reported her missing Sunday morning when he awoke and couldn't find her in the family home. The front door to the home was open, but the father said he did not know whether his daughter had opened it and wandered off or not.

Fox told police he had gone to a concert with friends Saturday night and left Riley and her brother, Tyler, 7, with their grandparents. The children's mother, Melissa, had gone to Chicago to participate in Sunday's breast cancer walk.

Kevin Fox said he picked up the children about midnight and put them to bed about a half hour later.

The Wilmington Police Department authorized a statewide Amber Alert on Sunday afternoon, police said. But the alert was called off about three hours later when her body was found.

"We have no doubt foul play was involved," said Pat Barry, a spokesman for the Will County Sheriff's department.

"But I don't believe there is a mass murderer or anything like that walking around the streets of Wilmington," he added.

An autopsy is scheduled for Monday.