At least 60 inmates in a Brazilian jail have reportedly been killed - a number brutally - during a prison riot.
The disturbance broke out in the northern state of Amazonas on Sunday afternoon, lasting until the following morning.
Some of the deaths were reportedly very grisly - with inmates beheaded and dismembered.
Several prison guards were held hostage during the riot, in which a number of detainees also escaped from the jail.
It is believed at least 60 serving prisoners died, making it one of the country's largest prison massacres.
"This is the biggest prison massacre in our state's history," state public security secretary Sergio Fontes said during a press conference.
Brazil has been plagued by prison violence in recent months, with rival gangs believed to be behind it.
Opposing gangs are said to be engaged in a battle to gain control of several prisons, with Monday's violence the latest episode of the feud.
Fontes confirmed that many of the dead had been beheaded while others had been quartered.
Officials reportedly found a hole bored into a prison wall which had been used to smuggle weapons inside.
The state security secretary said that the inmates had made few demands to end the riot, which concluded when the final 12 prison staff were freed.
In another prison in Amazonas on Monday, 87 inmates managed to successfully escape.
Hours after the latest riot, video footage emerged of distraught family members desperately trying to make their inside the facility.