By Brian Winter
SAO PAULO (Reuters) - Small but violent protests in several Brazilian cities this week have added to a sense of growing unrest in Brazil at a time when inflation, crime and President Dilma Rousseff's popularity are all taking a turn for the worse.
An estimated 5,000 protesters, including many university students, blocked main avenues and vandalized buildings in central Sao Paulo, causing traffic chaos for the fourth time in eight days on Thursday. When police tried to disperse the crowd, violence erupted, injuring dozens and leading to nearly 200 arrests.
Demonstrations also were held in Rio de Janeiro and the southern city of Porto Alegre, raising the prospect they could spread as Brazil prepares to host soccer's Confederations Cup - a warm-up event for next year's World Cup - for two weeks starting on Saturday.
Police have taken an increasingly hard line against the protests, firing rubber bullets and tear gas, injuring several bystanders and journalists covering the demonstrations. One widely circulated image showed police firing pepper spray at a TV cameraman filming the protests in Sao Paulo.
The crackdown has touched a nerve in a country that endured two decades of repression under a military dictatorship that ended in 1985.
The protests themselves have rallied around opposition to a 10-cent hike in bus and subway fares to the equivalent of about $1.60, leading some pundits to blame them on inflation running at 6.5 percent annually and an economy that has cooled down considerably after last decade's boom.
Those issues contributed to a decline of 8 percentage points in Rousseff's public approval rating in a poll released this week, although it still remains high at 57 percent.
Interviews with protesters indicate a wide range of grievances, from rising murder rates to anti-abortion laws to growing frustration with insufficient and overcrowded public transportation.
Many of the protesters in Sao Paulo appeared to be middle-class university students, carrying smartphones and high-end cameras, while local media reported a significant presence of left-wing political parties.
Some said they were inspired by protests in Istanbul - "Peace is over, Turkey is here!" was one chant on Thursday night. Others said they opposed the notion of bus and subway fares at all, arguing public transportation should be free.
'A PIECE OF TRASH'
"This city's a piece of trash and we shouldn't have to pay anything for terrible services," Lucia Pereira, a 19-year-old student, told local TV in Sao Paulo.
After previous protests severely disrupted traffic and damaged storefronts and subway stations in Sao Paulo, a metropolitan area of about 20 million people and Brazil's financial capital, local authorities promised not to let a tiny group wreak havoc again - a stance supported by editorials in the city's two largest newspapers.
"Vandalism, violence and obstruction of public roads are not acceptable," Sao Paulo state Governor Geraldo Alckmin wrote on Twitter on Thursday night as the crackdown was taking place.
"The right to free protest is a basic pillar of democracy. So is the right to come and go and the right to protect public property," he added.
A survey of Sao Paulo residents by polling firm Datafolha, taken before Thursday night's protest, indicated that 55 percent of respondents supported the demonstrators, although 78 percent thought they had been too violent.
Demonstrators said they planned another march in Sao Paulo for Monday evening. Twitter and other social media crackled on Friday morning with calls for more students to join upcoming marches.
Sao Paulo's newly elected mayor, Fernando Haddad, said he would not backtrack on the fare increase, but he also expressed regret over the violence.
"On Tuesday, I think the image was of violence by the protesters," he told reporters. "Unfortunately, (Thursday), there's no doubt that the image was of police violence."
Haddad is a prominent member of Rousseff's left-leaning Workers' Party, and finds himself in the uncomfortable position of having to confront a cause many in the party support. Alckmin, a former presidential candidate, is from the more conservative PSDB, the leading opposition party.
(Editing by Todd Benson and Will Dunham)