A teenage girl arrested over a random attack with a knife in Tokyo's Shibuya Ward has said she stabbed two people she came across because she "wanted to practice" killing her mother and "wanted to get the death penalty," the police have said.

The girl, who was arrested Saturday on the spot on suspicion of attempted murder, has been identified as a 15-year-old junior high school student from Toda, Saitama Prefecture. Her name has been withheld because she is a minor.

Police turned over the case to prosecutors on Monday.