South African taxi drivers on Friday blocked roads around Johannesburg's main international airport to protest against ride-hailing company Uber, causing some passengers to miss their flights.

The protest by drivers with metered cabs, who say Uber unfairly siphons business from them, caused morning traffic jams on two highways near O.R. Tambo International Airport. Police later cleared the roads.

The impact of the blockade will continue "to be felt throughout the day due to earlier delays, particularly on flights that need to return to O. R. Tambo International Airport", Airports Company South Africa, which manages the airport, said in a statement. 

"Airlines have informed the airport that passengers that missed flights in the morning are being accommodated on other flights."

South African Airways urged passengers to arrive at the airport earlier than usual, even if they planned to fly later in the day.

In a statement, Uber said many South African drivers with metered taxis are also picking up customers with its ride-hailing app.

"Our technology is open and pro-choice and we are keen to offer it to a broad number of taxi drivers to boost their chances for profit", said Uber, adding that threats and intimidation toward Uber drivers are unacceptable.

Meanwhile, some Uber drivers protested outside the company's Johannesburg office on Friday, local media reported. That group of protesters reportedly said Uber does not do enough to address their safety concerns.

Taxi drivers in some other countries also have protested, sometimes violently, against Uber because of concerns over allegedly unfair competition.

AP