More than five million Sydney residents will spend at least another week in coronavirus lockdown, Australian authorities said Wednesday, after detecting another 27 new cases.

Stay-at-home orders have already been in place in the country's biggest city for two weeks, as authorities try to curb an outbreak of the highly contagious Delta variant.

More than five million Sydney residents will spend at least another week in coronavirus lockdown
More than five million Sydney residents will spend at least another week in coronavirus lockdown AFP / Bianca De Marchi

State officials said progress had been made, but light-touch measures -- allowing residents to leave home for work, exercise and shopping -- needed to continue.

"This Delta strain is a game changer, it's extremely transmissible," said New South Wales premier Gladys Berejiklian, saying it must be eradicated from the community.

Images from outside a Covid-19 vaccination hub in Sydney as a citywide lockdown is extended. More than five million Sydney residents will spend at least another week in coronavirus lockdown.
Images from outside a Covid-19 vaccination hub in Sydney as a citywide lockdown is extended. More than five million Sydney residents will spend at least another week in coronavirus lockdown. AFPTV / Andrew LEESON

"We don't want to be in a position where we are constantly having to move between lockdown, no lockdown, lockdown, no lockdown."

Berejiklian said an extension -- which includes school closures -- was the "best chance of making sure this is the only lockdown we have until the vast majority of our citizens are vaccinated."

Stay-at-home orders have already been in place in Sydney for two weeks, as authorities try to curb an outbreak of the highly contagious Delta variant
Stay-at-home orders have already been in place in Sydney for two weeks, as authorities try to curb an outbreak of the highly contagious Delta variant AFP / Bianca De Marchi

The lockdown is now expected to end on Friday 16 July.

Australia's "Covid zero" approach has seen a series of snap lockdowns in cities across the country and its international borders closed for the last 15 months.

People sit in a quiet plaza in the central business district in Sydney, as the city remains in lockdown for a second week to contain an outbreak of the highly contagious Delta Covid-19 variant
People sit in a quiet plaza in the central business district in Sydney, as the city remains in lockdown for a second week to contain an outbreak of the highly contagious Delta Covid-19 variant AFP / Bianca De Marchi

The strategy has allowed Australians to live relatively normally throughout the pandemic, while avoiding the high death tolls seen around the world.

Since the pandemic began, Australia has detected just over 30,000 virus cases and reported 910 deaths.

But there are growing questions about how long the country can continue to fend off the virus and remain cut off from the rest of the world.

The Sydney outbreak has so far seen just 357 cases, underscoring the strictness of the strategy.

In contrast, Britain is considering lifting virus restrictions with 27,000 new infections each day.

A top health official this week likened Australians' efforts to get the jab to the "Hunger Games" -- a fictional battle-to-the-death contest.

Prime Minister Scott Morrison has outlined a four-step plan to allow the country to gradually open up when so-far-undefined vaccine targets are met.

Coronavirus