(CNN) -- At least two dozen people were sickened Wednesday at the Ross Correctional Institution in Chillicothe, Ohio, law enforcement officials said.
Authorities responded to the prison after reports that 24 people -- including prison guards, nurses and inmates -- were overcome after being exposed to a substance, according to the state highway patrol. They were taken to Adena Regional Medical Center, the highway patrol's statement said.
"Several doses of Narcan were administered to victims, and an additional 300 Narcan doses are available at the facility," the statement said. "The contaminated cell block has been cleared, and all persons from the contaminated area have been temporarily relocated within the facility. A hazardous material decontamination team is en route for cleanup."
Narcan is commonly used to treat opioid overdoses, but it's not known what the substance was at the prison.
Troopers said the facility is secure and there is no threat to the public. Authorities are investigating.
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