Rie Chisaka, a 41-year-old part-time worker in Ikoma, Nara Prefecture, was arrested Thursday after she called the police to report that she had stabbed her 8-year-old son's female classmate.

The responding officer found the suspect with her son and the victim. Police said the girl, also 8, was stabbed in the chest several times with a knife. Although severely injured, she was still conscious while being transported to a hospital. The boy was not present during the attack, police said.

A 60-year-old woman living nearby said she heard a child's scream around the time when the incident happened.

"Chisaka just moved to the house this autumn," the woman's 70-year-old husband added. "She did not look like a person who stabs kids."