More than a million Brazilians poured into the streets of at least 80 cities in the largest anti-government demonstrations yet.
Violent clashes broke out in several cities as people demanding improved public services and an end to corruption faced tear gas, pepper spray and rubber bullets.
At least one protester was killed in Sao Paulo state after a car rammed into a crowd of demonstrators, the driver apparently angered about being unable to drive along a street.
President Dilma Rousseff called an emergency meeting about the protest with top cabinet members yesterday, after a largely silent and much criticised response to the protests.
There were also growing calls on social media and in mass e-mails for a general strike next week, a move that might bring in unions and other organised groups to what has so far been an explosion of discontent over everything from high crime to poor education.
In Rio de Janeiro, where an estimated 300,000 demonstrators swarmed into the seaside city's central area, running clashes played out between riot police and clusters of mostly young men, their T-shirts wrapped around their faces. But peaceful protesters were caught up in the crackdown, too, as police fired tear gas canisters into their midst and at times indiscriminately used pepper spray.
Thundering booms echoed off stately colonial buildings as rubber bullets and the gas were fired at fleeing crowds.
Foreign Minister Antonio Patriota, for one, hit back at protesters the morning after his modernist ministry building in Brasilia was attacked by a boisterous crowd. At one point, smoke billowed from the building, and windows were shattered along its perimeter.
Standing before the battered ministry, he said he "was very angry" that protesters attacked a structure "that represents the search for understanding through dialogue".
At least 40 people were injured in Rio, including protesters like Michele Menezes, a wisp of a woman whose youthful face and braces belie her 26 years. Bleeding and with her hair singed from the explosion of a tear gas canister, she said that she and others took refuge from the violence in an open bar, only to have a police officer toss the canister inside.
"I was leaving a peaceful protest and it's not the thugs that attack me but the police themselves," said Menezes.
Despite the crackdown, protesters said they would not back down.
"I saw some pretty scary things, but they're not going to shake me. There's another march on the 22nd and I'm going to be there," said 19-year-old university student Fernanda Szuster. By evening, the number of protesters had swelled to a million, according to local police estimates from cities across Brazil.
Clashes were also reported in the Amazon jungle city of Belem, in Porto Alegre in the south, in the university town Campinas north of Sao Paulo and in the northeastern city of Salvador.
"This was meant to be a peaceful demonstration and it is," said artist Wanderlei Costa, 33, in Brasilia. "It's a shame some people cause trouble when there is a much bigger message behind this movement. Brazil needs to change, not only on the government level, but also on the grass roots level. We have to learn to demonstrate without violence."
Despite the energy on the street, many protesters said they were unsure how the movement would win real political concessions. People in the protests have held up signs asking for everything from education reforms to free bus fares while denouncing the billions of public dollars spent on stadiums in advance of the World Cup soccer and the Olympics.
"It's sort of a Catch-22," Rodrigues da Cunha said. "On the one hand we need some sort of leadership, on the other we don't want this to be compromised by being affiliated with any political party."
Additional reporting by Reuters