The carnage which erupted today has left 52 dead with 16 beheaded according to military police.
Detainees belonging to criminal gangs in the Altamira Regional Recovery Centre in Para, north Brazil fought battles for over five hours.
According to the chief of Para’s prison system, Jarbas Vasconcelos, the clash erupted between rival gangs and spiralled into a full scale rebellion.
Two prison officers, held hostage, were released.
“We have 52 dead, including 16 beheaded. It is still very hot inside the prison, and we are working to remove bodies”
Susipe superintendent Jarbas Vasconcelos
There is no information as to whether they suffered any injuries.
According to Susipe, the riot began when inmates in block A, where members of one of the gangs are housed, stormed the annex holding a rival faction.
Doors in the block were allegedly locked by the invading criminals and preliminary reports indicates that inmates set fire to mattresses.
Videos taken inside the prison and obtained by FocusOn News show the fire engulfing the block with flames rising above the fencing. At the top of an open section prisoners are filmed kicking a head around on the floor.
Sounds of bloodcurdling screams can be heard above the commotion from those believed to be under attack.
Additional footage, not shown by Daily Star Online because of the horrific nature of the scenes, shows the heads of decapitated inmates lying on the floor.
In the horrific images, perpetrators of the attack kick the bloody remains around the floor.
The deadly clash started around 7am and was brought under control by 12pm by the Tactical Operational Group of the Military Police of Pará who were called in to quell the riot.
They worked with representatives from the prison system to negotiate the release of hostages.
The prison has a capacity of 208 but is reported to be overcrowded with 372 inmates.
Susipe superintendent Jarbas Vasconcelos said he is launching an investigation into how prison intelligence and surveillance systems failed to anticipate the deadly rampage.
He said: “The unit is old and it houses two criminal factions (Red Command and the Class A Command).
“We had no reports from our intelligence of the possibility of an attack of this magnitude.
“We have 52 dead, including 16 beheaded. It is still very hot inside the prison, and we are working to remove bodies.”
This is the second largest prison massacre in 2019.
In May, 55 inmates were killed in prisons in Amazonas state.