A spokesman says the fight happened Wednesday morning at the facility in the Mott Haven section, which just opened on Monday, and the officers were hurt trying to get it under control.
The union says all 20 officers were taken to local hospitals for treatment.
The Horizon Juvenile Center has been taking in 16- and 17-year-old Rikers Island inmates under the state's new Raise the Age legislation that treats 16- and 17-year-olds as juveniles instead of adults.
The union notes that correction officers can't use pepper spray at Horizon like they can at Rikers Island, so they must use force to get inmates under control.
"We can call them kids, whatever they want," COBA President Elias Husamudeen said. "This place has to be shut down until it can be made safe. It needs to be shut down. It wasn't ready October 1, and it's not ready today."
There was no immediate comment from the Department of Correction, but the Administration for Children's Services -- which operates both Horizon and the Crossroads Juvenile Center in Brownsville -- released the following statement:
"We are in a transitionary period for a historic reform that's never been done before, and there have been some incidents involving youth and officers, which were quickly addressed. None of the injuries were serious, but we take these and all incidents seriously."
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