Rio de Janeiro is kicking off the five days of over-the-top parades and raucous, alcohol-soaked street parties that make up its world-famous Carnival celebrations.

Rio Mayor Eduardo Paes on Friday handed over the keys of the city to King Momo, the mythical jester who reigns over the extravaganza.

This year's celebration will be a chance for Brazilians to forget the recent avalanche of bad news, from a stalling economy to rising crime to an ongoing corruption scandal at state-run oil giant Petrobras.

More than 450 street parties are slated to bring millions of people onto Rio streets, including some 970,000 tourists. Paes says the visitors are expected to inject around $780 million into the local economy.

Carnival wraps up on Wednesday.