A notorious Brazilian drug gang is being held responsible for a prison riot that left at least 33 inmates dead – some of which were decapitated. The mass killings come just three days after a further 56 inmates were slaughtered during a disturbance at another jail in a neighbouring state.

The riot at the Monte Cristo Rural Penitentiary, in the capital of the northern state of Roraima, Boa Vista, was triggered after a group of prisoners reportedly escaped from an area of the jail at 2.30am on Friday 6 January.

The inmates reportedly broke locks on their cells and invaded a separate wing of the building before attacking a rival gang. According to the prison's governor, Brazilian special forces were needed to restore order inside the prison which housed 1,400 inmates, double its capacity.

The local secretary of justice, Uziel Castro, told the BBC he blamed the violence on the Sao Paulo-based Primeiro Comando da Capital (PCC) in English, First Capital Command, drug gang which are believed to be the largest gang in Brazil.

The PCC reportedly have a presence in 22 of the country's 27 states, as well as in neighbouring Paraguay and Bolivia. Castro added that when guards re-entered the prison , they found several men decapitated.

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Relatives of prisoners reacts as they wait for news in a checkpoint close to the Roraima state's largest penitentiary where at least 33 people were killed during a riot, Roraima, Brazil, January 6, 2017. REUTERS/JPavani

In October this year at least 25 inmates were killed in deadly clashes at the very same prison. Shocked police discovered that seven prisoners were beheaded, while six were burned to death in the incident.

This riot took place during visiting hours, when prisoners broke padlocks and released other inmates held in another wing the prison. Inmates took over 100 visitors – mostly women – hostage and threatened to throw hog-tied prisoners off the roof of the prison.

Sunday's prison riot in Manaus was the deadliest in Brazil in years with 87 prisoners managing to escape and 47 still at large. During the 17-hour riot PCC members clashed with members of a rival gang, Family of the North (FDN), a powerful local gang.

It has not been revealed if police believe the two prison riots are related.

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Police car drives to the Monte Cristo, Roraima state's largest penitentiary, where around 33 people were killed during a riot, Roraima, Brazil, January 6, 2017. REUTERS/JPavani