Political march or soccer riot? In Brazil, it's hard to tell

Shortly after he was accosted while waiting for a bus in an affluent Brazilian neighbourhood, Igor posted a warning on Facebook to friends and family.

His message? Don't get caught wearing a red shirt by an irate gang of anti-government protesters. They'll take it as a sign of support for the embattled and scandal-ridden government even if it bears the innocuous image of Homer Simpson.

"This shirt has always been a joke among my friends, as they say it is my self-portrait," Igor, who asked that only his first name be used, wrote online in Portuguese. "I was suddenly startled when a black car, carrying a Brazilian flag from its window, passed by really close to me and yelled,'You s----y petralha!'"

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A petralhais pejorative nickname for a supporter of the governing Workers' Party. They tend to wear red.

Anti-government protesters prefer green and yellow the colours of both the Brazilian flag and its national soccer team which, for many Brazilians, is one of the highest symbols of national pride.

Igor was accosted on March 17, the day President Dilma Rousseff named her former mentor, ex-president Luiz Inacio Lula da Silva, as her chief of staff, escalating tensions between those in favour of the current government and those who oppose it.

Several cases like his have been reported in recent months as the tension and violence on the streets has come to resemble what the Brazilian media calls a "Fla x Flu."

The term refers to a showdown between Rio de Janiero's most famous football rivals: Flamengo FC and Fluminense FC.

Tense rivalry

It also describes any "passionate and tense rivalry," says Fred Melo Paiva, a football commentator and columnist at Estados de Minas, a major Brazilian newspaper.

"It is also related to fanaticism a denial of the other's opinion, and a lack of desire for any deals or concessions with the other party. In football it is a feeling of eliminating your opponent in a decisive final match."

Paiva also compares the recent turmoil with the bad behaviour of the torcidas organizadas highly organized groups of football fans.

"Torcidas organizadas get organized to support their teams in stadiums during match day, but there is also an historical presence of violence among them, like the hooligans in the U.K.," he said in Portuguese.

"On match day, violence is expected between opposing teams. Inside or outside of the stadium."

But lately, the colours of your clothes are something to pay attention to before venturing out into the streets of Brazil.

Red-clad supporters of the Workers' Party have often clashed with the green-and-yellow anti-government crowd, which is calling for Rousseff to be impeached.

Government supporters consider this attempt at a right-wing coup, but do not necessarily support the government. Instead, they defend the right of the current government to stay in power.

Others wear black, representing mourning for Brazil and a complete lack of trust or hope in this government, or in Brazil's political systems in general.

Tease, provoke and diminish

The similarities with football go even further, including the pejorative nicknames for opponents, supporting chants and security measures for demonstration days.

"The organized fan groups create nicknames to tease, provoke and diminish each other. This, of course, emphasizes violence and rivalry," says Paiva.

"The same is observed between the two opposed political groups. Supporters of the impeachment are called coxinhasby the petralhas."

Those names also make implications about class. Flamengo is viewed as the people's team, while Fluminense is for the elites.

Coxinhasrefers to snobbish, conservative behaviour.Petralhais a play on P and T the initials of the Workers' Party, in Portuguese and "thief."

Both sides have the right to protest on the streets, but are scheduled on different days so police can control the crowd and maintain safety.

Protest days look a lot like football showdowns: Large groups of demonstrators wearing their "team's" colour go to the streets, wave flags and chant either "Fora Dilma!" (Out, Dilma) or "No vai ter golpe!" (There will not be a coup!) with samba drums on the side.

Brazil's lower house will vote on Sunday about whether Roussef could legally be impeached.

The expectations "feel like a football championship final," says Paiva, "and it is been prepared as such."

The safety measures include a wall ("ridiculous," he says) that divides the lawn in front of the national congress, like the divisions used to keep opposing fans apartstadiums.

As for the results of Sunday's "finale," Paiva says he is hopeful.

"Football is a 'little box of surprises,' like we say in Brazil. Or 'a funny old game' as it is referred to in the U.K. There is no other sport that offers so much twists and turns during the match. We never know the results. Till the referee blows his whistle, nothing is guaranteed."