The uprising at the Guarapuava prison in the south of the country began on Monday when inmates on a work detail over-powered guards, taking 12 of them hostage on the building's roof.Authorities trying to gain control of the prison uprising managed to win the release of one of 12 prison guards yesterday, but the others have been stripped naked, tied up and badly beaten by masked prisoners gathered on the rooftop, in scenes that have shocked Brazil.The Parana state justice secretariat said a group of more than 30 prisoners was leading the rebellion at the Guarapuava prison, and that an unknown number of other inmates were involved.There are about 250 inmates in total at the facility some 550 miles southwest of Rio de Janeiro.The inmates have a long list of demands, including better food, treatment, conditions and the transfer of some prisoners to other penitentiaries.It's the latest rebellion to hit a prison in Brazil, where severe overcrowding and poor infrastructure lead to dozens of uprisings each year.(dailymail.co.uk)Bakudaily.Az