Health officials said Sunday they had detected the Covid Omicron strain in Australia for the first time in two passengers who were tested after flying into Sydney from southern Africa.
The eastern state of New South Wales' health authority said it had conducted urgent genomic testing and confirmed the new strain was present in the two people who landed in Sydney on Saturday.
They tested positive for Covid shortly after arriving, leading to an urgent analysis for possible infection by the heavily mutated Omicron strain.
"The two positive cases, who were asymptomatic, are in isolation in the special health accommodation. Both people are fully vaccinated," NSW Health said.
Another 12 passengers from southern Africa on the same flight did not test positive for Covid but had been placed in quarantine, it said.
About 260 passengers and crew on the plane have also been told to isolate, the health authority said.
The plane with the infected passengers landed on the same day that Australia announced it was banning flights from nine southern African countries including South Africa and Zimbabwe.
- 'Get vaccinated' -
The arrival of the new variant comes just a month after Australia lifted a ban on citizens travelling overseas without permission, with the country's border also set to open to skilled workers and international students by year's end.
After more than 18 months of closed borders, fully vaccinated Australian citizens no longer have to seek an exemption to leave the country.
On March 20 last year Australia introduced some of the world's toughest border restrictions in response to the coronavirus pandemic.
For almost 600 days, countless international flights were grounded, and overseas travel slowed to a trickle.
Quarantine arrangements for returning vaccinated residents depend on where they arrive in Australia.
While Sydney has scrapped quarantine for returning travellers, other Australian states with lower vaccination rates still have mandatory and costly 14-day hotel quarantine requirements.
It is unclear whether the arrival of the new variant will lead to a return to tighter rules.
Speaking a few hours before the confirmation that the Omicron strain had arrived in Australia, New South Wales Premier Dominic Perrottet seemed reluctant to commit to any new restrictions.
"We need to learn to live alongside the virus and also live alongside the various strains of the virus that will come our way," Perrottet said.
"The best thing that we can do is to get vaccinated and get booster shots," he added. "There are limits to what the state and federal government can do."