Rio's carnival kick-off

A float of the Grande Rio Samba school

Rio's carnival parades kicked-off on Sunday night in a burst of colour, music and costumes.

This year's party is expected to be the biggest ever, with most schools of samba celebrating the 500 years since Portuguese explorers landed in Brazil on 22 April 1500.

"We wanted to make this the biggest Carnival, investing in a theme that is timely and important," said Armando Martins, a spokesman for the city's tourism department.

On Sunday and Monday nights 14 schools of samba, which together invested more than $13m, compete for the prize of Carnival Champions.

No expense spared on costumes

Every school has about 4,000 dancers, giant allegorical floats, colourful costumes and energetic rhythms.

Selected judges will give them points in nine different categories - such as best song, floats, dancers' performance and costumes.

Traditional groups like Mangueira, Portela, Viradouro, Beija Flor, Mocidade Independente and Salgueiro are among the favourites.

The parades will run until Ash Wednesday, when the carnival ends.

Sambodrome

The parades take place in a specially build sambodrome - a 700-metre avenue blocked off for the purpose.

More than 300,00 tourists have invaded the city and 70,000 spectators are expected to pack the sambodrome for the two nights of official competition.

Some 4,000 police are on duty each night at the Sambodrome and 32,000 others are patrolling the streets and the shantytowns.

Their aim is to curb drug trafficking, which doubles during Carnival, according to the police.

Controversy

But controversy had arisen even before Rio's schools of samba had sewed the last sequins on their costumes.

Fourteen samba schools will take part in the parade

Acting on the request of the city's archbishop, police confiscated a four-metre cross and a giant pink and purple painting of the Virgin Mary that were to appear on a float.

Revellers and Catholic Church officials have repeatedly locked horns over the use of religious images in the parades.

The Church says is illegal and qualifies as blasphemy under Brazil's criminal code.

But late on Friday, Unidos da Tijuca school won a court order allowing it to recover the confiscated items and use them on its floats.

The school is scheduled to take part in the parades on Monday night.