Since then, there appears to have been a wave of retaliation from a gang known as the PCC, or First Command of the Capital.

BBC: Sao Paulo sees big jump in murders

In 2006, members of the First Command of the Capital gang unleashed a wave of violence and riots in almost all of Sao Paulo's prisons to prevent being transferred.

BBC: Police on patrol in Paraisopolis

More than 130 people have died in the last two weeks as part of a conflict between the police and the gang, known as First Command of the Capital (PCC).

BBC: Brazil: 13 new deaths in Sao Paulo's gang battle