At least 12 guards and several inmates are being held hostage after a prisoner uprising in southern Brazil, during which some of those incarcerated were tossed from the roof of the correctional facility.
No deaths were yet reported at the Guarapuava prison as of late Monday, authorities said, as negotiators worked to end the standoff with inmates who complained of poor treatment and bad food.
At least eight people were reported injured, including six who were thrown from the roof of a building.
The uprising at the prison, which houses nearly 250 prisoners, began when about 40 inmates on a work detail over-powered guards.
Live television images showed hooded prisoners armed with knives and clubs on the roof of a prison building, making threatening gestures towards disrobed guards, whose hands were tied behind their backs.
The Parana state justice secretariat, in charge of prisons, said its director was negotiating directly with the inmates holding the guards and fellow prisoners captive.
It is the latest uprising at a prison in Brazil, where severely overcrowded conditions and poor security lead to several such rebellions each year.
In late August, inmates beheaded two prisoners during an uprising in the same state where Monday's incident occurred.