At least 52 prisoners have been killed by other inmates during a riot at a prison in northern Brazil on Monday.
Officials say 16 of the victims were decapitated, and others were asphyxiated. Inmates also set part of the Altamira prison on fire, preventing authorities from entering parts of the facility. The riot involved rival criminal gangs. Two prison officers who were taken hostage have since been freed. The violence began at around 07:00 local time (10:00 GMT), and ended at around noon. The two rival gangs involved have not been named by authorities. The prison in Altamira has a capacity of 200, but was occupied by 311 prisoners. A string of deadly violence that has plagued Brazil's prisons in recent months. The country has the world's third-largest prison population of some 700,000 people.
Killings between rival gang members are common in Brazilian prisons. Human rights groups have accused the government of doing too little to prevent the violence at prisons that have become recruitment centers for gangs. Brazil's President Jair Bolsonaro has said he wants to impose tighter controls in the country's prisons, as well as building many more of them.