Rio de Janiero: Demonstrators and police have clashed in Sao Paulo during the first in a planned series of anti-World Cup protests called by radical activist group Anonymous across Brazil.

With less than five months before the June 12 kick-off - when the five-time champions and hosts take on Croatia - Brazil is facing the same kind of social rumblings that marred last year's Confederations Cup dress rehearsal.

People help a family out of a burning car after it drove over a barricade of fire started by protesters in Sao Paulo, Brazil. Credit:Getty Images

Anonymous called for Saturday's protests against football's fabled event via its Facebook page under the slogan, "The Cup will not take place."

Other activists said "FIFA go home" on Twitter, referring to football's world governing body, which was likely watching the weekend's events with some concern.