Around 25 kilometers from the area, Miyako Hiraoka, a first-year student at the University of Shimane in Hamada, Shimane Prefecture, had been missing since failing to return to her dormitory after finishing her shift at a part-time job on the evening of Oct. 26.

A joint investigation squad of the Shimane and Hiroshima prefectural police has determined through the autopsy that Hiraoka was killed within five days after going missing, investigative sources said.

It has also found that her head, which was found on a gentle slope near the top of the 1,223-meter Mt. Garyu by a man picking mushrooms, has signs of blows to the face, the sources said.

As no bloodstains or personal effects were found near the site, the police suspect the head was transported there from a different place.

The joint squad is now investigating where she went after her part- time job and checking out her contacts, the sources said.

Hiraoka could not be reached on her mobile phone and the police released a photograph of her Monday.