Dutch health authorities said Saturday that 61 passengers from two flights from South Africa tested positive for Covid-19 and the results were being examined for the new Omicron variant.

The people who tested positive were now being quarantined in a hotel near Amsterdam's Schiphol Airport, where the 600 people on board the two planes from Johannesburg spent hours waiting on Friday.

"We now know that 61 of the results were positive and 531 negative," the Dutch Health Authority (GGD) said in a statement. 

"The positive test results will be examined as soon as possible to determine whether this concerns the new worrisome variant, which has since been given the name Omicron variant."

EU health authorities have said the new strain poses a "high to very high risk" to the continent.

All passengers who tested positive must stay in quarantine at the hotel for seven days if they show symptoms and for five days if they do not, the GGD said.

Passengers who tested negative, but who are remaining in the Netherlands, are expected to isolate at home. 

"We understand that people are frustrated by this," the statement added, "people have just made a long trip with the idea that they will shortly be home," it said.

"Instead just after landing, they are confronted with a situation we have never before experienced in the Netherlands, namely that people have to be tested at Schiphol and are forced to wait until they get a result."

Those who do not live in the Netherlands can "continue their journey", it said.

Australia bans Africa flights

Australia banned flights from nine southern African countries on Saturday, tightening its borders to prevent the entry of the new Covid-19 Omicron variant.

Non-Australians who visited South Africa, Zimbabwe and several other nations in the past fortnight will also be barred from Australia, Heath Minister Greg Hunt said.

Citizens and residents travelling from the listed countries will have to quarantine for 14 days.

"These are strong, swift, decisive and immediate actions," Hunt told media in Canberra.

The variant -- which has a large number of mutations -- was first detected on November 9.

Scientists are racing to understand how it behaves, but there are fears the strain may be more transmissible or render existing vaccines less effective.

The World Health Organisation listed Omicron as a variant of concern and said it could take several weeks to know if there are significant changes in transmissibility, severity or implications for Covid vaccines, tests and treatments.

UAE says 100% of population received one Covid jab

One hundred percent of the United Arab Emirates' population has received at least one dose of a vaccine against Covid-19, the health ministry has said.

The announcement late Friday came amid growing global concern over a new Covid variant dubbed Omicron that was first detected by South Africa.

The World Health Organization said the new variant is more infectious than the dominant, highly transmissible Delta strain, and several countries, including the UAE, have restricted travel from a number of south African countries.

According to the UAE health ministry, "a total of 21,802,032 doses" of Covid vaccine have been administered in the Gulf Arab nation.

"One hundred percent (of the population) have received one dose" while "90.18 percent are fully vaccinated".

The UAE -- a federation of seven emirates -- is home to around 10 million people, a majority of whom are expats.

The energy-rich Arab country was considered as far back as July a leader in terms of population in inoculating people against Covid.

In October, the UAE declared it had overcome the coronavirus crisis after recording its lowest number of infections that month.

The UAE has so far recorded more than 741,000 cases of Covid-19, including 2,145 deaths.