Australia's second most populous state will deploy Australian Defense Force personnel to the homes of people who have tested positive and who have not answered telephone calls, in order to kick start the contact tracing process, state premier Daniel Andrews said.

A flare-up of infections in Melbourne, the state's largest city, prompted the government to enforce a six-week partial lockdown and make face masks mandatory for its residents or risk a A$200 ($143) fine.

"This is about going that extra step to make sure that we cannot just call but we can connect... get that interview done and then begin the process of tracing contacts," Andrews told a regular press conference.

"If you were door knocked and you were not found at home...that would almost certainly lead to you being fined."

The state recorded six deaths overnight, the highest daily toll for the nation since the pandemic began.

All the deaths were linked to aged care homes, of which more than 40 have recorded outbreaks. Statewide, 300 new infections were found, dropping from a record of 484 on Wednesday.

Two cases were detected among Aboriginal people in the regional Victorian city of Ballarat, a cause of concern for officials given a high degree of health issues among Indigenous Australians.

"No-one should be moving towards trying to provide definitive commentary that we have turned a corner," Andrews added.

NSW tightens restrictions

Australia has so far escaped the high COVID-19 casualty numbers of other nations, with just over 13,300 infections and 139 deaths from the virus as of Friday.

In the most populous state of New South Wales, restrictions were reintroduced on Friday after several clusters emerged, including dozens of cases stemming from a Thai restaurant. New cases in the state fell to seven overnight, from several days in the teens.

Group bookings at restaurants, cafes and clubs will be limited to 10 people and patrons inside a venue will be capped to 300.

Wedding and corporate events will be limited to 150 people with strict social distancing rules including a ban on singing, dancing and mingling, while only 100 can attend funerals and places of worship.

Australia's National Cabinet met on Friday and laid out new measures to combat the virus including tougher restrictions on truck drivers transporting goods between states, some of which have not seen any cases of community transmission for months.

Prime Minister Scott Morrison reaffirmed the country's aggressive suppression strategy to stamp out all community transmission, even as it looks to soften the economic blow.

Australia's budget is set to plunge into its biggest deficit since World War Two this year as the coronavirus crisis knocks the country into its first recession in three decades and forces policymakers to roll out hundreds of billions of dollars in stimulus.