Brazil's Carnival got into full swing on Sunday night, as six elite samba schools paraded through the Sambadrome in downtown Rio de Janeiro.

A troupe opened the parade with an ocean theme, including mermaids. As a highlight of celebrations, the parades are taking place over two nights.

They pit the top 12 samba schools against each other to compete for the champion's crown. Despite money being tight due to the financial crisis, the schools' enthusiasm remains high.

Besides the parades, hundreds of street parties and celebrations outside the Sambadrome have also attracted more than a half million people from around the world.