According to the media agency Agencia Brasil, at least 56 prisoners were killed in a 17-hour riot at an Anisio Jobim Prison Complex over the weekend. The uprising started on Sunday as a result of a feud between two criminal organizations within the Manaus prison, as reported by Agencia Brasil.

The two agencies, Familia do Norte and the Primeiro Comando da Capital, began the riot over control of drug trades within the prison, which was controlled by the Familia de Norte according to state media.

At least six people were decapitated as bodies were thrown over the complex wall. The hostages included 74 prisoners and an undetermined number of guards, according to Sergio Fontes, the public safety secretary. It is unknown how many prisoners may have been able to escape the complex.

Fontes reported that forces negotiated with the prisoners on the basis of human rights. They did not enter the facility due to the dangerous and “unpredictable” situation. However, he assures that the instigators of the riot will be held responsible for the murders, as well as other crimes. He also says that the incident was premeditated and “planned over a long period of time,” despite the inmates’ promise to the prison administration that “everything would run smoothly throughout the holidays.”

Brazil’s justice minister, Alexandre de Moraes, told reporters that those responsible would be transferred to federal prisons. The government of the state of Amazonas wishes to fight drug trafficking by strengthening the security in these centers in Brazil. To that end, it requests federal support.

According to the Agencia Brasil report, “dozens” of prisoners at the Antonio Trindade Penal Institute were trying to escape as the riot unfolded at the other prison, possibly intending to distract the authorities from the events unfolding at Jobim.

At yet another penitentiary, there was a “commotion” at the same time, according to the public security official.