By Pedro Fonseca
RIO DE JANEIRO (Reuters) - The climax of a major international soccer tournament that provided the backdrop for the biggest mass protests to sweep Brazil in 20 years was set to kick off late Sunday as scattered demonstrations proceeded amid an otherwise festive feel.
A deployment of about 10,000 police and other security forces was largely idle before game time as Brazil, playing in Rio's Maracanã stadium, geared up to play Spain, the reigning world champions, in the final of the Confederations Cup.
The tournament, which began two weeks ago, is a warmup to the World Cup, which Brazil will host next year.
Ticket holders, revelers and curious onlookers converged on the stadium despite a few small demonstrations that are part of an ongoing wave of protests in Latin America's biggest country.
After a decade-long economic boom that has now cooled, Brazilians have taken to the streets in recent weeks to protest against poor public services, inflation, rising crime and a host of other ills.
The marches, which drew over a million protesters in more than 100 cities at their peak this month, have used the ongoing soccer tournament as a stage from which to vent their grievances. Many Brazilians are outraged that the country is spending about $14 billion to host the World Cup at a time when schools, hospitals, roads and public security are in dire need of investment.
President Dilma Rousseff, whose approval ratings have plunged since the protests began, was initially expected to attend Sunday's game - a major event in soccer-crazed Brazil. But, taking note of the discontent of voters, she decided not to attend after she was booed at the tournament opener in Brasilia.
On Saturday, polling firm Datafolha said Rousseff's approval rating sank by 27 percentage points in the last three weeks. Though the numbers fell from what had been consistently high ratings previously, the precipitous drop suggested that the demonstrations could pose a serious threat to her likely re-election bid next year.
Early on Sunday afternoon, a group of about 5,000 protesters marched peacefully near the Maracanã stadium. Other groups also marched later in the day.
(Writing by Paulo Prada; editing by Todd Benson and Christopher Wilson)