The Osaka Prefectural Police arrested a 30-year-old woman Monday for allegedly lifting her 9-month-old daughter up high, then dropping the girl, causing her to suffer a fatal head injury in January.

The mother, Hiromi Nasu, owned up to the charge, saying she was stressed out from caring for her three children, the others being 2 and 3 years old.

"I grabbed her by her clothes, lifted her high and dropped her. Soon she became motionless," the police quoted her as saying about the killing of her daughter, Yuzuha.

According to the police, Nasu dropped her second daughter on her back in their apartment sometime between 6:10 p.m. and 8:00 p.m. on Jan. 9. The girl died on Jan. 15 at a hospital in Osaka where she was taken after suffering acute subarachnoid hematoma.

Nasu called an ambulance at around 8:00 p.m. on Jan. 9, claiming she had heard her baby crying and had discovered she had fallen out of her bed.

The girl was in a coma when she was taken to the hospital. Medics told the police that the victim, who had suffered a fractured skull, showed signs of having been abused.

Nasu initially claimed that her daughter had hit her head on the floor when she fell out of the bed.