Non-essential businesses in Australia's second-biggest city of Melbourne were ordered Monday to close for six weeks as officials struggle to control a growing coronavirus outbreak.

Victoria State Premier Daniel Andrews said most retail outlets in Melbourne would have to shut from midnight Wednesday into Thursday, with exemptions for supermarkets, pharmacies and liquor stores.

The measures are the most restrictive Australia has seen since the epidemic began and came on top of mandatory mask-wearing, stay-at-home orders and a night-time curfew in the city.

A woman walks out of a near-deserted Flinders Street Station in Melbourne after the state announced new restrictions to contain coronavirus
A woman walks out of a near-deserted Flinders Street Station in Melbourne after the state announced new restrictions to contain coronavirus AFP / William WEST

The closures are aimed at helping ensure an estimated one million fewer people are moving around the region for work, as hundreds of coronavirus cases continue to be recorded daily despite a lockdown that began in early July.

"As heartbreaking as it is to close down places of employment... that is what we have to do in order to stop the spread of this wildly infectious virus," Andrews told a press conference.

"This six-week period is absolutely critical."

A man walks past a virus-theme decorated tree in Melbourne
A man walks past a virus-theme decorated tree in Melbourne AFP / William WEST

Other sectors -- such as meat production and construction -- will be required to scale down significantly from Friday.

Australia's Victoria state has state imposed fresh, sweeping virus restrictions, including an overnight curfew in Melbourne for the next six weeks.
Australia's Victoria state has state imposed fresh, sweeping virus restrictions, including an overnight curfew in Melbourne for the next six weeks. AFPTV / Cameron Dale

Andrew urged people not to panic buy.

"I can't guarantee that every single product at exactly the volumes you would like to buy will be there, but there will be enough for people to get what they need."

An overnight curfew was imposed Sunday and people banned from moving more than five kilometres (about 3 miles) from home.

Melbourne residents must also stay at home from 8 pm to 5 am until at least September 13. Only those carrying out essential work, or seeking or providing care, are allowed out.

Those caught breaking the rules can be slapped with a fine of Aus$1,652 ($1,177) from police who are patrolling the city's streets, though Andrews said "significant boosts" to penalties would be announced Tuesday.

The radical new restrictions set Melbourne apart from the rest of Australia, where most regions have significantly relaxed restrictions as just handfuls of new cases are reported daily.

Victoria state now has almost 6,500 active coronavirus cases, recording 429 new cases and 13 deaths from the virus Monday.

In Melbourne, weddings have also been banned, in-person religious services cancelled and students are poised to return to online lessons.

Australia's total reported infections topped 18,000 on Monday, with 221 deaths, from a population of 25 million.

Coronavirus Australia