Prisoners at a Saitama Prefecture police lockup in November stole keys from an officer and temporarily freed more than 20 fellow prisoners who then fought with a group of officers trying to restrain them, prefectural police disclosed Thursday.
The incidents took place at the Koshigaya police station.
Police sent papers to prosecutors Thursday accusing two of the prisoners of causing bodily injury and obstructing official duties.
Then station chief, Takashi Ehara, has had his salary cut by 10 percent for four months due to the incidents, while 16 other officers incurred temporary salary cuts or warnings over the prisoners' subsequent treatment.
The melee took place in the evening on Nov. 14 when a guard entered a prisoner's cell to watch him prepare for bed. The prisoner suddenly screamed while at the same time two other prisoners attacked one of the station's inspectors.
The group then threatened a deputy inspector, ordering him to hand over the keys he was carrying. The men used the keys to open the other cells, releasing their fellow prisoners.
The fight apparently ensued when a group of 30 officers were returning the men to their cells. Three of the officers sustained light injuries.
Also, before the incident, some of the prisoners at the facility had been allowed access to the station's floor containing women's cells, and received cigarettes and food on inappropriate occasions, police officials said.
Kenji Oyama, of the prefectural government's police affairs department, offered an apology to the people of Saitama over the incidents.
"This is something that should never have occurred," he said in reference to the prisoners' improper treatment. "I want to issue strict guidance on the detention system to ensure that a second incident does not occur, and I want to try to restore trust."