A teenage Japanese boy walked into a police station with a severed head and claimed he killed his sleeping mother a day before her birthday in northern Fukushima state Tuesday.

The police followed the boy to his house later and recovered a headless body from his house.

The 17-year-old boy, who was living with his brother, claimed he killed his mother all alone. "It didn't matter who I killed," Kyodo news agency quoted the boy, who had been given psychiatric treatment in the past, as saying.

This is the latest grisly murder in the country that has been witnessing a series of cases involving dismembered bodies. A woman killed her husband and scattered body parts around Tokyo in January. Police also had recovered a human leg from a river just a day before.

The incidents come as a shock to Japanese people as the country is known for its low crime rate.