The protesters blocked one of Sao Paolo's highways with stones and sticks to remonstrate against a controversial decision to clear the city slums in a multi-million dollar program to improve living standards and 'reinstate property rights.'
Sao Paulo, the world's third-largest metropolis has a population of around 11 million.
The favelas, home to around 6 million of the city's residents, sprang up towards the end of the 19th century when freed slaves moved to the area building homes on unclaimed land, they were later joined by migrants and many families have lived on the city's steep hillsides for generations.
Brazilin President Luiz Inacio Lula da Silva announced a revitalization program for favelas that often lack sewage systems, fresh water, electricity and policing.
