Fifty thousand people took to the streets of Sao Paulo and in the vicinity of Rio de Janeiro on Tuesday to protest the recent hike in bus fares, criticize corruption and demand improvements in public services.

A small group of demonstrators attacked the Sao Paulo City Hall and forced the municipal guard to take refuge inside the building. Later the crowd threw fence barriers and other objects at the windows, breaking a number of them, and wrote graffiti on the outer walls.

However, shortly thereafter another group of demonstrators replaced the fence barricades in front of the City Hall and made a human cordon there to prevent acts of violence against the building while they chanted "Without violence."

According to the Datafolha Institute, some 50,000 people participated in the protests on Tuesday after about 65,000 turned out to demonstrate in Sao Paulo the day before.

The protesters occupied the central Praça da Se plaza, in front of the Sao Paulo Cathedral and some of the nearby streets, and they booed people who waved the flags of political parties, apparently in an attempt to preserve the non-political nature of the demonstration.

They also approached City Hall again, near the square, and burned in effigy a two-faced image with Sao Paulo Mayor Fernando Haddad, a member of the governing Workers Party, or PT, on one side and state Gov. Geraldo Alckmin, the head of the opposition Brazilian Social Democratic Party, or PSDB, on the other.

This is the sixth demonstration staged in Sao Paulo since city authorities in early June raised the price of public transport from 3 reais (about $1.50) to 3.2 reais (about $1.60), sparking the protests.

Thousands of people also participated in protests in São Gonçalo, in the Rio de Janeiro metro area and city authorities in at least six Brazilian cities on Tuesday announced reductions in public transport fares.

Haddad, who initially had said it would be impossible to reduce fares in Brazil's biggest city, later said that he will review the figures to seek alternatives.

The protests began last week in Sao Paulo and at first were exclusively against the hike in public transportation fares, an issue that galvanized the public to express latent social discontent.

Now, the protesters' demands have broadened to include greater investment in health care and public education and criticism of the government's costly programs to organize high-profile sports events such as the Confederations Cup and the 2014 World Cup. EFE