[BUENOS AIRES] Uber, the smartphone app that connects riders and drivers, launched on Tuesday in Buenos Aires without authorisation, triggering protests by taxi drivers who blocked major avenues and snarled traffic.
"The Uber smartphone app will be available as of 1600 hours today Buenos Aires time, and can be downloaded at the App Store," the San Francisco-based company said on Twitter.
Although ride-hailing apps have risen rapidly to become a booming industry, they face stiff resistance from traditional taxis and bans over safety concerns and questions about legal issues including taxes.
Taxi drivers often complain that Uber drivers do not pay for permits or taxes; Uber argues it is not a transport company like taxi firms - just an app.
"What they are doing is illegal. They are not delivering transport under existing laws," Buenos Aires transport chief Juan Jose Mendez told TN television.
The Argentine capital's sprawl engulfs 13 million people, and millions more commute in and out every day.
The city alone has some 38,000 taxis.
Uber does not employ drivers or own vehicles, but uses private contractors with their own cars instead, allowing them to run their own businesses.
Licensed taxi drivers, who must undergo hundreds of hours of training in some countries, accuse Uber of endangering their jobs by flooding the market with cheaper drivers who need only a GPS to get around.