Police in Otsu, Shiga Prefecture, said Friday they have arrested a 20-year-old woman on suspicion of abusing her one-month-old son by biting him on the arm.

According to police, the mother, who hasn’t been named, is a university student, Sankei Shimbun reported. She was arrested on Thursday and has admitted to the allegation, police said.

Police said the incident occurred sometime between 6 p.m. on Sept 3 and 7 a.m. the next day. The woman bit her son on his left arm. She took him to a hospital where doctors notified a child welfare facility about a possible case of abuse.

The child’s injury took about a week to heal, police said. He was taken into protective custody on Sept 5.

Police said the mother has not attended any classes at university since April.

© Japan Today