Protesters massed in at least seven Brazilian cities Monday for another round of demonstrations voicing disgruntlement about life in the country, raising questions about security during big events like the current Confederations Cup and a papal visit next month.

Authorities had hoped to avoid the sort of bloody confrontations that shocked Sao Paulo last week and the outpourings of dissent were mainly peaceful. But small bands of protesters broke glass trying to get into the main congressional building in Brasilia, and some demonstrators clashed with police in Rio de Janeiro.

The unrest initially was set off last week by anger over a 10-cent hike in public transport fares, but protesters have moved beyond that issue to tap into widespread frustration in Brazil over a heavy tax burden, politicians widely viewed as corrupt and woeful public education, health and transport systems.

Tear gas, rubber bullets

Police commanders had said publicly that they would try to avoid violence Monday, but warned they could resort to force if protesters destroyed property.

Demonstrators try to enter a building during a protest in downtown Rio de Janeiro. (Sergio Moraes/Reuters)

Officers in Rio fired tear gas and rubber bullets when a group of protesters invaded the state legislative assembly and threw rocks and flares at police. Police in the capital of Brasilia, however, did not use force when about 200 demonstrators broke from a crowd of 3,000 and climbed up to the roof of the Congress building after shattering glass walls trying to get inside.

Tens of thousands of people turned out for a peaceful protest in Sao Paulo, where riot police had charged into another calm crowd on Thursday firing rubber bullets and tear gas and beating some demonstrators. Some protesters turned out in clown costumes complete with red rubber noses. Samba percussion circles, including one led by a drag queen with a blond wig and oversized dollar-sign earrings, pounded out competing rhythms.

Most of the thousands who protested in Rio did so peacefully, many of them dressed in white and brandishing placards and banners. Many people in the city left work early to avoid traffic jams downtown.

In Belo Horizonte, police estimated about 20,000 people joined a peaceful crowd protesting before a Confederations Cup match between Tahiti and Nigeria as police helicopters buzzed overhead and mounted officers patrolled the stadium area. Earlier in the day, demonstrators erected several barricades of burning tires on a nearby highway, disrupting traffic.

Protests also were reported in Curitiba, Belem and Salvador.

Marcos Lobo, a 45-year-old music producer who joined the protest in Sao Paulo, said the actions of police during earlier demonstrations persuaded him to come out Monday.

"I thought they (the protests) were infantile at first because of my preconceived notions," Lobo said. "Then I saw the aggression."

'Everything in Brazil is a mess'

Another protester, Manoela Chiabai, said she wanted to express her dissatisfaction with the status quo.

"Everything in Brazil is a mess. There is no education, health care — no security. The government doesn't care," the 26-year-old photographer said. "We're a rich country with a lot of potential but the money doesn't go to those who need it most."

In a brief statement, President Dilma Rousseff acknowledged the protests, saying: "Peaceful demonstrations are legitimate and part of democracy. It is natural for young people to demonstrate."

Ariadne Natal, a professor at the University of Sao Paulo whose research focuses on violence, said protesters want to "take advantage of this moment when we have foreign visitors, when the world's press is watching, to showcase their cause."

"The problem we've seen is that the police action is trying to prevent these protests," she said. "What we need to figure out is how the protests as well as the big events can be carried out democratically."

Brazilians have long accepted malfeasance as a cost of doing business, whether in business or receiving public services. Brazilian government loses more than $47 billion each year to undeclared tax revenue, vanished public money and other widespread corruption, according to the Federation of Industries of Sao Paulo business group.

But in the last decade, about 40 million Brazilians have moved into the middle class and they have begun to demand more from government. Many are angry that billions of dollars in public funds are being spent to host the 2014 World Cup and 2016 Olympics while few improvements are made elsewhere.

Protests are routine in Brazil, but few turn violent. Security experts say the demonstrations aren't the main danger for the hundreds of thousands of visitors who will descend on Brazil from now through the Olympics in 2016.

However, Joe Biundini, whose FAM International Group provides security details to executives attending the Confederations Cup, said there is a danger of escalating violence from the protests if authorities don't negotiate with demonstrators.

"If the government doesn't sit down with them it could get worse in future matches," Biundini said.