"This is not a quick thing," Brislin said. "They continue to assess the entire situation."
Prisoners started some of the fires in trash cans, and flames eventually spread, shooting into the air during the riot. Several buildings were seriously damaged at the Northpoint Training Center, a medium-security facility about 30 miles south of Lexington.
Officers in riot gear rushed in with tear gas, and all the inmates were subdued within two hours, authorities said. They were kept in the prison yard and authorities surrounded the facility so no one could escape.
Eight inmates were taken to the hospital and eight prison workers were injured and helped at the scene. Four inmates remained hospitalized Sunday, but two were expected to be released to the Department of Corrections later in the day, Brislin said.
Brislin said investigators will interview inmates and review security videos to see what caused the riot. "They haven't even started interviews yet," Brislin said.
About 500 inmates remained at the prison. The others were taken to facilities across the state.
The remaining inmates at the prison were being housed in a 196-bed dorm that was not severely damaged, the prison chapel, gym and a unit of 60 single cells, said Mendalyn Cochran, a spokeswoman for Northpoint Training Center. Another 40 minimum-security inmates were being housed on the grounds outside the main fence, Cochran said.
The melee came two weeks after more than 1,000 inmates rioted at the California Institution for Men in Southern California. That prison was designed to hold about half as many inmates, although investigators say they don't know if crowding helped spark the racially charged riot.
Northpoint opened in 1983 and has a staff of 285.