Workers hold replicas of World Cup trophies at a plant in Dongguan, Guangdong Province on Wednesday. Dongguan Weiguang Giftware Ltd, the authorized producer for World Cup souvenirs, produced more than 8 million items, which are sold across the world. Photo: IC

After years of preparation plagued by construction delays, budget overruns and violent protests, Brazil Thursday kicked off the month-long World Cup, igniting the enthusiasm of soccer fans around the world.

The 32-team extravaganza gets under way in the teeming mega-city of Sao Paulo, where the host nation's beloved Selecao faces Croatia before 61,600 supporters and a worldwide television audience of several hundred million.

Twelve government leaders or heads of state were among the VIPs at Thursday's opening ceremony.

In the final hours before the opening ceremony, Rio de Janeiro, the venue for seven Cup games including the final, appears to be ready. Dozens of helpful World Cup staff offer information at airport arrivals. FIFA's ticketing collection center is running smoothly and the Maracana stadium is clearly signposted. But the preparations will not be truly tested until the city hosts its first game between Argentina and Bosnia-Herzegovina on Saturday.

The journey to Rio's southern beach districts from the Joan Antonio Jobim International Airport in the north highlights much of the contrast that people were expecting with Brazil hosting the World Cup. Youths from the surrounding favelas in football shirts climb through gaps pried in highway fences to hawk food to slowing motorists while military police carrying automatic weapons watch from the roadside. All along the route, wherever there is a hard court large enough to play, there is some sort of soccer match, from favela pickup games to organized leagues in Rio's wealthier southern districts.

Brazilian flags fly from nearly every window. Visible support for the Selecao spans the wealth gap with flags adorning work trucks, taxi wing mirrors, shanty town shacks and the imposing fences of gated communities in Ipanema.

Despite the atmosphere of enthusiasm in most of the city, striking airport ground staff in Rio de Janeiro blocked the road leading to the city's international airport Thursday. The protesting workers, who have declared a 24-hour partial strike, invaded Avenida Vinte de Janeiro and managed to completely close it in one direction for around 10 minutes before military police intervened and partially reopened the road, said news website G1.

While protests have marred the run-up to the tournament in Rio and Sao Paulo, nearly all the 3 million tickets available for the 64-match tournament have sold out, reported the Associated Press.

"The financial success - we have it, it is done," FIFA secretary general Jerome Valcke was quoted as saying. "The ticket sales success is there, we have never sold so many tickets."

But the joy for "financial success" was not shared across Brazil. After years of apathy and simmering resentment at the tournament's record $11 billion price tag. Many Brazilians were grudgingly embracing World Cup fever.

The multi-billion-dollar cost of the World Cup has angered many in a country which has chronically under-funded health and public services and rampant violent crime.

Rage at poor public services morphed into a nationwide movement during last year's Confederations Cup test event, with deadly clashes rippling across the nation.

Protests and labor strikes are planned in the 12 host cities, including a 24-hour slowdown by some airport workers in Rio although the threat of a long subway strike in Sao Paulo has eased.

On Thursday, police fired noise bombs to disperse a crowd of about 200 demonstrators, who were trying to cut off a key avenue leading to the Corinthians Arena in Sao Paulo, reported Reuters.

Brazil's President Dilma Rousseff warned that her government would not tolerate a repeat of last year's protests. "We will guarantee the security of Brazilians and of those who come visit us," she said.

A vast security blanket is being deployed for the World Cup, with 150,000 soldiers and police on duty along with 20,000 private security officers.

The tournament, held every four years, is the world's most-viewed sporting event. CNN said its viewership is set to smash TV records. The event "could prove even more popular than the 2008 Beijing Olympics, which reached a global TV audience estimated at 3.6 billion people," it reported.

From the host country, viewed as a spiritual home of soccer, to Europe, and from Africa to Asia, fans have been anticipating the soccer carnival.

In China, the national team's failure to qualify for the tournament has not stopped enthusiasm for the event.

With the earliest kick-offs in the initial group stages at midnight Beijing time, fans will need stamina to watch them.

Despite the unsociable hours, bars and restaurants across the nation have tuned their TVs in to the coverage in a bid to cash in on the event.

World Cup-related topics were trending high on Chinese social networks. A thread about the World Cup-opener between Brazil and Croatia received more than 262,000 posts, while another on the most memorable World Cup moment received more than 412,000 comments.

A vote on Sina Weibo asked Net users to choose their favorite teams. Germany led the vote, while China, the only team not competing in the tournament, came second, followed by Brazil and Spain.

The Chinese team only made it to the World Cup once in 2002, and has been under mounting criticism for failing its fans.

Despite the absence of Chinese players in Brazil, the nation has made a significant contribution.

The official match ball, known as the Brazuca, was designed by adidas and manufactured in China, along with copies of the mascot Fuleco. At least eight stadiums were built with the help of equipment from Changsha-based Sany Group, and nine stadiums use security inspection products from Beijing-based Nuctech.

Many fans will arrive at the Maracana stadium on subway trains produced by China CNR Corp Ltd. In Curitiba, another host city, energy-saving buses produced by CSR Corp Ltd will shuttle fans to the stadium.

Agencies contributed to this story