At least 57 prisoners were killed by fellow inmates during a prison riot in northern Brazil in what authorities have described as a "targeted act" by gang members directed at a rival group.
The riot at Altamira prison began early Monday and lasted throughout the morning, according to authorities. Two prison officials were reportedly taken hostage, but later released after negotiations.
In a statement put out by Pará state, where the prison is located, officials said that the riot was triggered when members of the Comando Class A gang set fire to a cell where rival gang members from Comando Vermelho (Red Command) were kept.
Most of the inmates that died were killed in the fire, officials said, but at least 16 of them were decapitated.
"It was a targeted act," state prison director Jarbas Vasconcelos said in a statement, according to Reuters. "The aim was to show that it was a settling of accounts between two gangs."
Vasconcelos said the fire spread through an old wing of the prison where prisoners were being held while a new building was under construction. According to The Associated Press, Altamira houses more than twice as many inmates as its maximum capacity.
Vasconcelos said the fire prevented police from entering the building for several hours.
As NPR's Philip Reeves reports from Rio De Janeiro, in some penitentiaries, criminal gangs have de facto control, and can easily access weapons; however, in this case, the number of dead is unusually high.
President Jair Bolsonaro was elected last year on a campaign promise to crackdown on crime, including in the country's overcrowded and often violent prisons.
As we reported in May, violent clashes at four prisons in the same general area of Brazil killed 55 people in violence that was also blamed on gangs.