A 15-year-old Japanese schoolgirl was arrested Sunday on suspicion of murdering a classmate and dismembering her body, local media reported.

The suspect, whose name was not released as she is a minor, has admitted to strangling the victim and severing her head and left hand, according to the Kyodo news agency.

She allegedly delivered blows to the head of 15-year-old Aiwa Matsuo with a metal instrument before strangling her in the city of Sasebo, in Nagasaki Prefecture, southwest Japan.

The victim's body was found on a bed in the suspect's apartment early on Sunday and investigators discovered tools nearby, reports said.

The suspect, who lived away from her parents though in the same city, told police she acted alone in the grisly killing, Kyodo added.

Matsuo had reportedly gone out to meet friends on Saturday afternoon, but her parents notified the police when she failed to return home at night.

The two girls graduated from the same junior high school.

Violent crime is still relatively rare in Japan but several high-profile cases in recent years have heightened public concern.

The city of Sasebo made headlines in 2004 when a primary schoolgirl stabbed her classmate to death.

In 2008 a man went on a stabbing rampage in a crowded Tokyo shopping street, killing seven people and wounding a dozen others.

That incident came seven years to the day after a knife-wielding janitor killed eight primary school children, leaving the nation in shock.

In 1997 a 14-year-old was arrested for the murder of two schoolchildren. The head of one of the victims was left in front of his school gates.