Protests blocked the Copacabana for half-an-hour as Brazil's ministers of culture and sport promoted this summer's showpiece tournament in the press auditorium
Hundreds of striking workers from the ministries of culture, education and health chanted against the government and displayed a banner reading "we don't want the cup" outside the Copacabana Fort.
Inside the fort, the minister of culture Marta Suplicy was telling a packed auditorium that the World Cup offers Brazil a chance to project "an image beyond samba music."
She was joined by sports minister Aldo Rebelo and a number of government and FIFA dignitaries in another embarrassing episode for tournament organizers just three days before the first game of the World Cup.
The protests spilled into the streets and blocked traffic heading along the Copacabana for at least half an hour.
Clashes between police and striking subway workers in São Paulo last week raised fears of a repeat of the nationwide protests that overshadowed the Confederations Cup last year.
The cost of hosting the World Cup was one of the main reasons that millions took to the streets in cities across Brazil last June to complain against poor public services and corruption.