RIO DE JANEIRO -- A month Brazil hoped would showcase its ability to play on the world stage has turned into days of massive protests highlighting long-standing problems simmering below the surface of the Brazilian success story.

Instead of abating after reversal of a bus fare increase — the catalyst for the protests — the demonstrations have grown in intensity, spreading to 100 Brazilian cities and towns.

Brazilian President Dilma Rousseff called an emergency meeting with Cabinet ministers Friday after a night when as many as one million Brazilians took to the streets to protest everything from corruption, inadequate healthcare and education, and high crime rates. Some also turned their wrath on expenditures and cost overruns on new soccer stadiums for the Confederations Cup that runs through the end of the month and the 2014 World Cup, also to be held in Brazil.

In an address transmitted on Brazilian television and radio Friday night, Rousseff asked for understanding about “the political and economic limitations’’ the country is facing and beseeched Brazilians not “to put at risk all that we’ve achieved. We have much to lose.”

But she pledged to create “a grand pact” to improve public services and said among her priorities would be to devote 100 percent of petroleum revenue to education, send thousands of doctors to rural areas, come up with a national urban transit plan and meet with peaceful protest leaders.

Things turned ugly late Thursday and Friday as police tried to quell protesters with rubber bullets, tear gas, and pepper spray. Two deaths have been attributed to the protests.

“I’m here because of the money that is robbed from us. A congressman gets a stipend for travel, clothes, and transportation while a favela resident earns 600 reais (about $257 a month),’’ said Ingrid Munique, 18. She joined the demonstrations in Rio de Janeiro with dozens of her neighbors from the Complexo Alemão favela who chanted, “I’ll give up the World Cup. I want money for health and education.’’

The protests represent a generalized discontent and a fear that hard-earned economic gains are in jeopardy, say analysts. The World Cup and 2016 Olympic Games, which will be held in Rio, have become convenient targets in the face of what many protesters view as inadequate public spending on transportation, hospitals and education.

“The Brazilian people are not against the World Cup, but they are against the exorbitant expenditures on stadiums,’’ said Edgar Reinoso, 61, as he coughed on tear gas during the Thursday night protest in Rio. “For Brazilians to come to the streets this way, it means a lot is wrong — mainly, corruption.’’

Riding a commodities boom in recent years, the Brazilian economy became a high-growth darling. Since 2003, some 40 million Brazilians have moved into the middle class. The rich have demonstrated their acquisitive power by snapping up luxury condos in Miami and even the middle class had begun to enjoy shopping trips to South Florida.

But the Brazilian juggernaut has begun to sputter. Last year, the economy grew a mere 0.9 percent, and although Brazil is near full employment, economic growth has remained stalled and inflation is rising.

“I think what you’re seeing in Brazil is a rising middle class whose position is somewhat tenuous but that wants to continue on an upward trajectory and don’t see how that’s going to happen,’’ said Barbara Kotschwar, a research fellow at the Peterson Institute for International Economics. She was in Brazil last week.