(CNN) At least 57 people were killed, including 16 who were decapitated, during a vicious gang battle that erupted in a prison in northern Brazil on Monday morning.

The unrest is reported to have begun when a local gang stormed a wing of the facility in Para state controlled by a rival group, state news reported. The majority of the victims are believed to have died from asphyxiation, after gang members set fire to part of the prison complex.

State media said the violence began around 7 a.m., local time in the Regional Recovery Center in the city of Altamira and lasted for several hours. Video of the scene showed prisoners sat on the roof of the building, brandishing knifes and with their heads covered, amid smoke rising from the interior.

Two correctional guards taken captive were released, state media reported.

Ten of the 16 prisoners who were blamed for instigating the violence will be transferred to federal penitentiaries, state media reported, citing local authorities. More than 46 other prisoners will be moved to other prisons in Para.

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