Taxi drivers blocked a central street in Montevideo on Friday to prevent ride-sharing service Uber from training new drivers as it seeks to roll out service in Uruguay.
"Get out, Uber pirates," shouted hundreds of taxi drivers after parking their vehicles in the middle of the street outside the hotel where the US-based company planned to hold a training session.
Leaders of the taxi drivers' union blocked the hotel lobby, mockingly pledging to sign up for the course.
"We're going to stay here and wait for them to hire us," said the union's president, Oscar Dourado, alleging Uber drivers would pay no taxes, insurance or permit fees.
"They came here to take away all the jobs in the formal sector," he told journalists.
"They already left taxi drivers jobless in Spain, Germany, Mexico."
He said the protest had prevented the company from holding the training.
"The class didn't happen. The teachers didn't show," he said.
Union leaders later met with Labor Minister Victor Rossi at his request.
Uber says it plans to give Montevideo residents "a reliable, classy, private-driver experience that they never knew existed."
Its planned Uruguayan rollout has already stoked controversy.
The southeastern department of Canelones said last week that it will fine drivers for the service and confiscate their license plates.
Uber's smartphone application, which connects users seeking rides with private drivers seeking clients, has shaken up the taxi market in more than 60 countries -- to sometimes violent protests from traditional taxi drivers.
Montevideo Mayor Daniel Martinez has vowed to regulate Uber, and met this week with company representatives.