Drug gangs sparked a prison riot that killed 56 people, with decapitated bodies thrown over prison walls in the bloodiest violence in more than two decades in Brazil's overcrowded prison system.
Sergio Fontes, the security chief for Amazonas state, told reporters on Monday several decapitated bodies were thrown over the wall of the prison in the Amazon city of Manaus, with most of those killed coming from the Sao Paulo-based First Capital Command (PCC) drug gang.
"This was another chapter in the silent and ruthless war of drug trafficking," he said.
Justice Minister Alexandre de Moraes travelled to Manaus on Monday to meet Amazonas Governor Jose Melo Oliveira and other federal security officials about the riot.
Pedro Florencio, the Amazonas state prison secretary, said the massacre was a "revenge killing" in a feud between criminal gangs in Brazil.
The violence began late Sunday and was brought under control by around 7am local time on Monday, Fontes said.
Just as the riot began in one unit of the Anisio Jobim prison complex, dozens of prisoners in the second unit started a mass escape in what authorities said was a coordinated effort to distract guards.
Overcrowding is extremely common in Brazil's prisons, which suffer endemic violence and what rights groups call medieval conditions with food scarce and cells so packed that prisoners have no space to lie down.
The Anisio Jobim prison complex currently houses 2230 inmates despite having a capacity of only 590.
Hours after the Anisio Jobim prison revolt ended, prisoners at an adjoining detention centre began a riot and attempted to escape. Authorities said the situation was quickly brought under control.
A total of 184 inmates escaped, with 40 recaptured by Monday afternoon.
The violence was the latest clash between inmates aligned with PCC, Brazil's most powerful drug gang, and a Manaus criminal group known as the North Family.
The Manaus-based gang is widely believed to be attacking PCC inmates at the behest of the Rio de Janeiro-based Red Command (CV) drug gang, Brazil's second largest.
Four inmates were later found dead in another prison in the rural area of Manaus, but state representatives were unable to clarify if a riot had occurred.
A group of inmates exchanged gunfire with police and held 12 prison guards hostage late on Sunday in the largest prison in Manaus, Globo TV reported.
Fontes said 74 prisoners were taken hostage during the riot, with some executed and some released.
