The city of Susono, Shizuoka Prefecture, filed a criminal complaint on Monday accusing the head of a nursery school of trying to cover up the alleged abuse of toddlers in its care, the city's mayor said.

The complaint against school head Toshihiko Sakurai came as three female former teachers were sent to prosecutors Monday by police after being arrested Sunday on suspicion of committing abuse, in June, such as hitting toddlers and hanging them upside down by their feet.

According to the complaint filed by Susono Mayor Harukaze Murata, Sakurai is suspected of making all school teachers write an oath to keep the abusive behavior secret and intentionally delaying the announcement of the incident to parents.