RIO DE JANEIRO (AFP) - Hundreds of taxis blocked main roads in Rio de Janeiro on Friday in a protest against Uber that underlined the potential for disruption when the city hosts the Olympics in four months' time.

"No to illegal taxis," read one of the slogans brandished by irate taxi drivers near Rio's domestic airport in the city centre.

"Whoever is against corruption doesn't use illegal taxis," read another, tapping into public disgust at a bribery scandal engulfing Brazil's government and business elite.

Some working taxis spotted with fares were stopped by their protesting colleagues. One woman told CBN radio she had to get three motorbike riders to take her, her husband and their baggage past the blockade to the airport.

The Rio taxi drivers are demanding that Uber, the successful US-based company whose ride-hailing via app is available in more than 60 countries, leave Brazil.

Uber has no authorisation to operate in Rio but continues to do so under a court injunction. It recently announced a push into emerging markets such as Brazil, and its fares undercut those of traditional taxis.

The company's passenger base in Rio has shown steady growth, as has the number of its drivers, as people seeking to escape climbing unemployment under Brazil's crushing recession sign on.

Rio's hosting of the Olympic Games in Aug 5-21 is expected to see many locals and visitors turning to Uber to get around - setting the scene for further taxi fury and possible protests.

Uber's roll-out around the world has prompted similar blowback from local taxi drivers fearing a threat to their livelihood.

They argue that Uber drivers, who are private contractors using their own vehicles, undercut them because they are not subject to the same costly training, insurance and safety laws taxi drivers face.