Australia and several other countries joined nations imposing restrictions on travel from southern Africa on Saturday after the discovery of the new Omicron coronavirus variant.
Omicron has been dubbed a "variant of concern" by the World Health Organization
It is potentially more contagious than previous variants of the disease and scientists are scrabbling to understand its mutations and find out whether current vaccines are effective against it.
At Johannesburg airport, cancelled flights and frustrated, stranded passengers.
"If I arrive in the UK after 4 pm, I have to quarantine in a hotel on my cost for 10 days. I don't have the money, I don't have the two thousand pounds to quarantine."
"I feel very sad for the people here as well going back on the red list again, and who knows for how long, not being able to see family."
The variant was first discovered in South Africa and has since been detected in Belgium, Botswana, Israel and Hong Kong.
A minister in the German state of Hesse said on Saturday that the variant had very probably arrived in Germany, in a traveller returning from South Africa.
Meanwhile, authorities in Amsterdam said that 61 out of around 600 people who arrived in the Dutch city on two flights from South Africa on Friday had tested positive for coronavirus.
Health authorities were carrying out tests to see if those cases involved the new variant.
Financial markets plunged on Friday, especially stocks of airlines, as investors worried the variant could cause another surge in the pandemic and stall a global recovery.