The jail guards' union is suing the city over what they say are unsafe conditions.
The Correction Officers' Benevolent Association claims sweeping changes in city jails are empowering violent inmates and endangering correction officers.
According to the suit filed in federal court in Manhattan, violence in city jails increased 18 percent since 2015, when the city implemented changes to how guards perform their duty.
The new policy came following several reports about the abuse of prisoners, particularly at Rikers Island.
The union is now seeking changes to the work environment and unspecified damages.
A city law office spokesman says the suit will be reviewed.