Dutch health authorities have announced that 13 cases of the Omicron coronavirus variant were found among passengers who were on flights from South Africa that arrived in Amsterdam on Friday.
The discovery of Omicron, dubbed a "variant of concern" last week by the World Health Organization, has sparked worries around the world that it could resist vaccinations and prolong the nearly two-year COVID-19 pandemic.
First discovered in South Africa, the variant has since been detected in Britain, Germany, Italy, Belgium, Botswana, Israel, Hong Kong and Australia.
Austria was investigating a suspected case on Sunday and in France Health Minister Olivier Veran said the new variant was probably already circulating there.
Omicron is potentially more contagious than previous variants, although experts do not know yet if it will cause more or less severe COVID-19 compared to other strains.
Countries have imposed a wave of travel bans or curbs on southern Africa. Financial markets dived on Friday as investors worried that the variant could stall a global recovery. Oil prices tumbled by about $10 a barrel.
On Sunday, most Gulf stock markets fell sharply in early trade, with the Saudi index suffering its biggest single-day fall in nearly two years.
In the most far-reaching effort to keep the variant at bay, Israel announced late on Saturday it would ban the entry of all foreigners and reintroduce counter-terrorism phone-tracking technology to contain the spread of the variant.
Prime Minister Naftali Bennett said the ban, pending government approval, would last 14 days. Officials hope that within that period there will be more information on how effective vaccines are against Omicron.
Many countries have imposed or are planning restrictions on travel from southern Africa. The South African government denounced this on Saturday as unfair and potentially harmful to its economy - saying it is being punished for its scientific ability to identify coronavirus variants early.
The Dutch government had already announced prior to the Omicron outbreak it was restricting evening activities following a sharp rise in the number of COVID-19 infections and patients needing hospital treatment.
The evening lockdown beginning on Sunday means shops, cultural venues, restaurants and sports clubs are required to close at 5pm.
Supermarkets are exempt from the measure, however.
The restrictions are initially due to apply until December 18.
Australian Associated Press