At least 24 inmates were involved in fights and altercations that locked down the Two Rivers facility Wednesday.

The 1,800 inmates at the medium security facility near Umatilla were locked down Wednesday morning shortly after 9am when several altercations broke out in the prison's general population living areas.  Officials described them as "mutual" altercations.

24 inmates were placed in "special housing" for their roles in the fights, two required minor medical attention.

Oregon State Police have launched an investigation, no word on if the lockdown has been lifted.