A performer from the Academicos do Salgueiro samba school parades during carnival celebrations at the Sambadrome in Rio de Janeiro, Brazil, on Sunday.

Rio de Janeiro - Celebrities flocked to Brazil to see the scantily-clad beauty queens and elaborate floats of the country's top samba schools compete on Sunday in the fiery main event of the famed Rio Carnival.

Over the next two nights, 12 schools will perform before a global television audience in the highlight of the five-day extravaganza, a fierce contest watched with the same fervour as football matches in this soccer-mad nation.

The school floats are packed with dancers wearing huge headgear, feathers, sequins, body paint - and little else.

The VIP guests at Rio's 72 500-seat open-air Sambodrome included 26-year-old American actress Megan Fox, of Transformers fame, who was hired to promote Brahma Beer, a popular Brazilian lager.

Other celebrities include reality television star Kim Kardashian and her boyfriend Kanye West; Italian bombshell Monica Bellucci and her French husband, actor Vincent Cassel; and Men In Black star Will Smith, who earlier visited the favela (shanty town) of Vidigal in southern Rio.

In the north-eastern city of Salvador, South Korean pop star Psy performed his hit Gangam Style to huge crowds on Friday alongside Brazilian stars Claudia Leitte, Gilberto Gil and Daniela Mercury.

US movie director Spike Lee was among the celebrity audience.

Unlike the ubiquitous Carnival street parties that are open to all, the Sambodrome parades are mainly for the wealthy and foreign tourists.

The country's biggest bash of the year is celebrated with great gusto across the country, and this year there is a special tribute to Koreans to mark the 50th anniversary of their immigration to Brazil.

Parades in Rio and Sao Paulo are honouring Korea's history and technological advancement, and the contribution made by the 50 000-strong Korean community to this racially diverse nation of 194 million people.

“It's a historic moment, a recognition of the contribution Koreans have made to Brazilian society,” said Marcelo Choi, vice president of the Sao Paulo-based Korean-Brazilian Association.

“The whole world can see that we are an integral part of the Brazilian family. So yes, it's a moment of great pride not just for us Korean-Brazilians but for Koreans around the world,” he told AFP.

Dubbed “the greatest show on Earth”, the Rio Carnival officially got under way on Friday, when the legendary King Momo received a giant key to the city.

Authorities said six million people, including more than 900 000 tourists, were expected to attend the five-day Rio bash.

Rio, which will host next year's World Cup and the 2016 Summer Olympics, has mobilised 14 500 police officers to provide security.

The first samba school to perform late on Sunday will be Inocentes de Belford Roxo, with a colourful homage to Korean culture on a theme called “The Seven Confluences of the Han River”, invoking the protection of the ancient Korean wind goddess Yondung Halmoni. - Sapa-AFP