CANBERRA • Australia's capital Canberra was ordered into a seven-day lockdown yesterday, after a single Covid-19 case was detected in the city that has largely avoided virus restrictions.

About 400,000 people in the country's political hub were under stay-at-home orders from 5pm local time, joining millions more already under lockdown in Australia's south-east.

"This is the most serious public health risk that we are facing in the territory this year. Really, since the beginning of the pandemic," said Australian Capital Territory Chief Minister Andrew Barr.

He added that the Covid-19-positive person had been in the community while infectious.

The authorities also appealed to residents to avoid panic bu-ying, as stores began to fill with maskless shoppers shortly after the announcement.

"There is no need for panic buying. And our key message to people is please be patient, be kind with one another and be thoughtful," said the capital's Health Minister Rachel Stephens-Smith.

Canberra has not been in lockdown since a nationwide shutdown in the early stages of the pandemic last year.

After months of pursuing a "Covid zero" strategy, Australia is struggling to contain multiple outbreaks of the highly transmissible Delta variant.

More than 10 million people in the country's biggest cities, Melbourne and Sydney, are currently in lockdown as the authorities try to bring case numbers down.

Much of western New South Wales state was also placed under lockdown late on Wednesday, amid concerns for a sizeable Indigenous population feared more vulnerable to the coronavirus.

"I ask all our Aboriginal community as well to please stay at home, come forward for a test if you have symptoms and of course please get vaccinated with any available vaccine as soon as you can," said New South Wales director of population and community health Marianne Gale.

New South Wales, Australia's biggest state economy, recorded 345 new cases yesterday, the vast bulk in Sydney. Daily case numbers have generally been on a steady incline since the outbreak started in Australia's largest city in mid-June.

Two more people in Sydney have died. The city is expected to spend at least nine weeks under stay-at-home orders, with several hot spot suburbs placed under harsher restrictions yesterday.

The country has recorded more than 37,500 cases of Covid-19 and 946 related deaths to date in a population of 25 million.

AGENCE FRANCE-PRESSE, BLOOMBERG