The government said Tuesday that it will look into child mistreatment cases at nurseries across the country and how municipalities have handled them, following the arrest of three nursery teachers in central Japan for allegedly abusing toddlers.

The case at the nursery in Susono, Shizuoka Prefecture, which also highlighted the municipality's late disclosure and the nursery head's alleged coverups, is "extremely regrettable" and "should not have happened," health minister Katsunobu Kato told a news conference.

Police arrested the three women on Sunday on suspicion of committing abuse toward the children in June such as by hitting the toddlers and hanging them upside down by their feet.

The Susono Municipal Government filed a criminal complaint Monday against the nursery school head on suspicion of harboring criminals.

The nursery's head also did not report the incident to city authorities or police despite a whistleblower coming forward from around June or July claiming abuse had been committed by some of the teachers, a source close to the municipal government has said.

The municipal government, meanwhile, has faced criticism for its slow response as it disclosed the case only last week, more than three months after it first received a tip about the abuse allegations in mid-August.

Through the probe that is set to begin soon, possibly by year-end, the central government is hoping to get a handle on mistreatment cases at nurseries and see whether municipalities are responding appropriately when they receive tips or hear of allegations.