A teenage girl was arrested in Kure, Hiroshima Prefecture, on Sunday after confessing to killing her friend and leaving her body on a local mountain.

The 16-year-old from Kure showed up at a police station Friday with her family and told officers that she killed a friend, also 16, who had been reported missing since late June. She admitted killing her when the two were on the mountain alone, and leaving her friend’s body there, the police said.

The police decided to launch an investigation at headquarters the same day because it was possible that a third person was involved.

The police found the body of a person believed to be the missing girl during a search of the mountain on Saturday.

The girl was arrested Sunday for abandoning a body and may be charged with murder.