Youths clashed with police in central Rio Monday as more than 200,000 people marched in major Brazilian cities to protest the billions of dollars spent on the Confederations Cup and higher public transport costs.
The nationwide demonstrations, the most extensive since the unrest began 10 days ago, were relatively peaceful.
However acts of vandalism were reported in Rio and Porto Alegre.
Police used tear gas, pepper spray and rubber bullets to disperse small groups of masked youths engaging in acts of vandalism near Rio's state legislative assembly. Some of the young people broke into the building and television showed a small fire.
Five policemen were reported hurt as 80 others holed up inside the assembly building which was surrounded by rowdy demonstrators.
Police could be seen around a vehicle masked vandals had set on fire.
Elsewhere in Rio, a host city for the Confederations Cup, police said around 100,000 marched, notably down Rio's central Rio Branco avenue.
In Brasilia, more than 200 youths briefly occupied the roof of the National Congress.
But after negotiations with police, the boisterous crowd agreed to leave, chanting and waving placards as security forces ringed the building. Some of the protesters called for the resignation of President Dilma Rousseff.
Later, an estimated 5,000 youths formed a human chain around the Congress building.
In Sao Paulo, the country's economic capital and most populous city, an estimated 65,000 staged a generally peaceful march, with no repetition so far of the violence that marred similar protests last week.
"Peaceful demonstrations are legitimate," said Rousseff in a bid to calm tempers. "It is natural for the young to demonstrate," she said in a statement posted on the presidency's blog.
"I came because I want Brazil to wake up. It's not just to protest the higher transport fares, but also because of shortcomings in education and health," said 20-year-old Diyo Coelho, who marched with friends carrying flowers in Sao Paulo.
Some 3,000 rallied outside Porto Alegre's City Hall, where police intervened after acts of vandalism by youths who set a bus on fire.
Some 30,000 protesters marched in Belo Horizonte, while smaller demonstrations were held in Fortaleza, Salvador and other cities.
"I am here to show that Brazil is not just about football and partying. We have other concerns, like the lack of investments in things that really matter, like health and education," said Daiana Venancio, a 24-year-old lawyer marching in Rio.
Earlier, Sports Minister Aldo Rebelo warned that that authorities would not allow the protests to disrupt international football tournaments Brazil has pledged to host -- the Confederations Cup and next year's World Cup.
"The government assumed the responsibility and the honor to stage these two international events and will do so, ensuring the security and integrity of the fans and tourists," Rebelo said.
But the spreading unrest is tainting the image of South America's dominant power as it hosts the Confederation Cup through June 30, in a dry run for the World Cup.
"As a Brazilian who travels daily in those packed buses and studies in a precarious university, I feel compelled to be part of this revolution," Gael Rodrigues Honorio,a 21-year-old engineering student at Brasilia University told AFP.
"This is just the beginning. We will get some improvements, at least with respect to transport and health," the student said during the Brasilia protest under the watchful eyes of some 400 police officers.
The protests over a hike in mass transit fares from $1.5 to $1.6 began 10 days ago in Sao Paulo, days before the opening of the Confederations Cup. The tournament brings together eight national teams from around the world in six Brazilian host cities.
The unrest rapidly spread to other cities with demonstrators focusing their anger not just on the transport fares but also on $15 billion the government is allocating for the Confederations Cup and the World Cup.
The demonstrators want these resources to be earmarked instead for health care and quality education in a country with vast economic disparity between rich and poor.
Saturday, around 1,000 of them managed to break through a security perimeter and protest outside the gate of Brasilia's national stadium during the Confederations Cup's opening game, in which Brazil trounced Japan 3-0.
Sunday, 3,000 people tried to break into Rio's renovated Maracana stadium where Italy defeated Mexico 2-1.
The Rio protesters, mostly by middle-class youths, railed against the police crackdown in Rio, Brasilia and above all Sao Paulo, where more than 230 people were briefly detained and about 100, including journalists, hurt last week.
"People are unhappy with various things, education: health, public transport," said Rogerio, a 25-year-old architect who did not want to give his last name as he joined Sunday's rally outside Maracana.
The unrest comes as Brazil is experiencing anemic growth (0.6 percent in the first quarter) while inflation reached an annualized 6.5 percent in May, the upper limit of the official target.
The disappointing indicators have dented the popularity of President Dilma Rousseff, particularly among the youngest and wealthiest Brazilians, recent polls show.
Rousseff was jeered in Brasilia Saturday as she inaugurated the tournament, although she retains high popularity and is favored to win re-election next year.