RIO DE JANEIRO - Glittering with sequins and sweat, thousands of performers shimmying to sultry samba beats danced their way down an avenue in Rio de Janeiro as the Brazilian beach city's famed carnival parades got under way.
With whimsical floats, thundering drum sections and legions of performers in fanciful, flesh-flaunting costumes, 12 samba schools are competing for the coveted title of carnival champions across two nights of epic booty-shaking.
Porto da Pedra, a school from the impoverished Sao Goncalo neighborhood, opened the festivities with a float topped by an enormous, roaring orange tiger that swatted out at the crowd with its claws, drawing shrieks of delight.
Rio has already been celebrating carnival for weeks with colourful, free-for-all street parties known as "blocos."
The parades are the climax: sumptuous festivals of colour and sound that last all night and into the next day.
Flying the colours of their favourite schools, a capacity crowd of 70,000 spectators cheered from the packed stands of the Sambadrome stadium, the city's purpose-built parade venue, with millions more expected to watch live on TV.
But there is more to carnival than all-night partying.
The samba schools are rooted in Rio's impoverished favela neighborhoods, and each parade tells a story, often dealing with politics, social issues and history.
This year's parades include homages to little-known heroes of Afro-Brazilian history and a celebration of the Yanomami Indigenous people, who have been ravaged by a humanitarian crisis blamed on illegal gold mining in the Amazon rainforest.