Anger has mounted in Brazil, where the construction bill for 12 stadiums has reached more than $3 billion. Miguel Schincariol/AFP/Getty Images

RIO DE JANEIRO — As the truncheon blows rained down on Vinicius Duarte, the 26-year-old university student tried to engage the police officers who continued beating him on the floor.

All he could hear were voices pleading with them to stop, as he suffered bruises and red welts across his face with every strike.

But the scene inside the Linson Hotel in São Paulo, where anti–World Cup protesters were taking refuge last weekend, was already out of control.

“If it was not me, it would have been someone else, because they've got a predisposition to violence,” Duarte, an industrial chemistry student, said after the demonstration. “It’s never happened to me directly before, but I’ve witnessed other people in the protests get the same savagery from the police.”

With less than six months until the 2014 FIFA World Cup, the anger that sparked the biggest uprising of a generation last year is still simmering in the host nation of Brazil, even if some of the momentum has been lost and the potential to disrupt the event remains unclear.

Police brutality has become a common backdrop to the demonstrations against substandard health care, education and transportation. Taxes remain high, the cost of living has increased and investment in the World Cup has spiraled out of control.

The protest that flared up in São Paulo last weekend, while demonstrations in other cities passed without incident, was indicative of the volatility of the movement.

In São Paulo, there were scenes of chaos as 2,500 people took part in a demonstration aimed squarely at the hosting of the soccer tournament.

The banners and chants were familiar: “FIFA go home” and “Hey, FIFA, pay my fare” — a reference to a rise in bus fares, which hits the poorest. Meanwhile, the construction bill for the 12 stadiums has reached more than $3 billion.

Even with the most recent increase in the minimum wage to $310 a month, the lowest-paid Brazilians still earn less than half the price of the most expensive World Cup ticket — $821.

And activists say as many as 250,000 people have been evicted or are threatened with eviction because of projects linked directly or indirectly to the World Cup.