More than 50 people have been killed in a prison riot in Brazil which saw rival gangs battle for five hours, officials say.
Gang members from one wing invaded another section of Altamira jail in Pará state, local media reported.
Officials giving a press conference said 16 of the dead were decapitated. Other reports said part of the prison was set on fire, suffocating many. Two prison officers who were taken hostage have since been freed.
In May, 40 people were killed on the same day in four different prisons in Manaus in Amazonas state – a day after 15 were killed in prison fights in the area.
