A 15-year-old schoolgirl has been arrested in Japan on suspicion of strangling and beheading her classmate.

The suspect, whose named has been withheld, reportedly admitted to strangling Aiwa Matsuo before severing her head and left hand in a brutal attack in the city of Sasebo in southwest Japan, Kyodo news agency reported on Sunday.

The police quote her as saying:

“I did it all by myself”

Matsuo’s dismembered body was discovered on Sunday morning on a bed in the apartment of the suspect, who was living independently from her parents.

Police were alerted after Matsuo’s parents reported that she had not come home on Saturday night after going to see a friend.

The murder comes a decade after another shocking crime in the city, when an primary schoolgirl stabbed her classmate to death in 2004.