The Justice Ministry on Monday said that "organizational and structural problems" at the nation's correctional facilities are behind recent cases of fatal abuse at Nagoya Prison.

The ministry released an interim report on two deadly assaults on prisoners by guards and another case of abuse that resulted in serious injuries at Nagoya Prison over the past two years.

The report says the crimes took place due to a "lack of human rights awareness" among guards in general, rather than individual problems of the guards being accused. The lack of such awareness can be attributed to the absence of a specific law that underscores the basic rights of prisoners or of guidelines to regulate the relationship between inmates and wardens, it says.