Traffic through South Africa's main airport was minimal on Thursday despite international flights resuming after a six-month ban, with last-minute government curbs leaving many would-be tourists unable to enter the country.

The government said on Wednesday it would not allow visitors from countries with currently higher coronavirus infection and death rates than South Africa.

That announcement, coming 12 days after President Cyril Ramaphosa said the country would re-open its borders, effectively cut out most of the tourist traffic that underpins its struggling economy.

The government also said it would revise the list of banned countries every two weeks, adding to uncertainty for the travel industry.

"The plan is riddled with muddled thinking," said David Frost, chief executive of Southern African Tourism Services Association (SATSA), which represents agents organising inbound travel.

"There is no way you can plan inbound tourism if a list is getting revised every fortnight."

O. R. Tambo International airport in Johannesburg was virtually deserted on Thursday, with just a handful of staff at ticketing counters and barely any travellers.

South Africa depends heavily on tourism, which prior to the pandemic contributed up to 3% of GDP and employed over 4% of the workforce, with travellers from Britain, the United States, Germany, France and The Netherlands among the biggest spenders.

Of those five countries, all but Germany are on the government's banned list.

South Africa is among the world's top ten in terms of total coronarvirus cases, at above 670,000, and has registered around 16,600 fatalities, but infection rates there have been falling since July.

Frost believes Europe, where a second COVID-19 wave now seems to be accelerating, could have been exempted from the ban. "We are in a ludicrous situation and dealing with a moving target," he said.

Andrew Stark, managing director of Middle East and Africa for Flight Centre Travel Group, an outbound travel agency, said the government's actions - as well as financial stress - had also deterred South African tourists from travelling abroad.

He predicted the outbound travel market would not return to its 2019 level of around R60-billion until 2023.