Uber, the international ride-hailing service, say some of their drivers are being harassed by taxi drivers in South Africa's largest city, Johannesburg.

Meter taxi driver Daniel Sejamoholo said drivers meeting on Tuesday decided Uber should not be allowed to work without an affiliation to a local taxi association.

South African media reported that cabdrivers intimidated Uber drivers last week, accusing the popular internet-based service of undercutting their profits.

In a statement, Uber said the incidents were isolated but it would send security to areas where harassment occurred. The company said it was trying to work with drivers.

Uber has faced opposition from cabdrivers in other cities including Paris, Mexico City and Sao Paulo, with conflict between cabbies and Uber drivers sometimes turning violent.