Police in a tweet cited Rio de Janeiro Federal University expert Moacyr Duarte as estimating the crowd at 300,000, but did not give their own estimate.
An AFP reporter yesterday said a small group of demonstrators hurled stones at police who responded with tear gas. At least one person was injured in the clashes.
On Wednesday, the protesters scored a major victory when authorities in Sao Paulo and Rio, Brazil's two biggest cities, cancelled controversial transit fare hikes, but that was not enough to placate the demonstrators.
Protesters say they want higher funding for education and health and a cut in salaries of public officials. They are also railing against what they viewed as rampant corruption within the political class
The mounting pressure on the government of President Dilma Rousseff in the face of the biggest street protests the South American country has seen in 20 years prompted her to cancel a trip to Japan planned for later this month.
