Victoria state has put in place a seven-day lockdown effective from midnight Thursday, while local residents were required to stay home except for essential business after a fresh outbreak of local transmissions.
Earlier in the month a man tested positive to the virus after becoming infected while undergoing hotel quarantine in South Australia and then flying into Melbourne and returning to his home in Wollert. These are: shopping for food and supplies, authorised work, care and caregiving, exercise with one other person for up to two hours, and getting vaccinated.
As first reported by Motorsport.com yesterday, six teams - Walkinshaw Andretti United, Erebus Motorsport, Team 18, Tickford Racing, Kelly Grove Racing and Blanchard Racing Team - are on standby to bolt from Melbourne to help ease concerns over border controls from other states.
A repatriation flight from India has landed in Melbourne hours before the state is plunged into a seven-day lockdown.
Unless there is a drastic improvement in the Melbourne situation, the affected teams will need to either be in NT quarantine, or be in another jurisdiction that has free access to the NT, by June 3.
"In the last day, we've seen more evidence we're dealing with a highly infectious strain of the virus, a variant of concern, which is running faster than we have ever recorded", Merlino said.
Australia has recorded about 30,000 Covid-19 cases to date - the vast majority in Victoria during last year's devastating second wave.
"We've seen overseas how hard that movement can be to control".
It is not yet clear how the virus got into the community.
Public gatherings are banned under the lockdown and restaurants, pubs and cafes can provide takeaway only. More than 40,000 test results were received overnight.
As of today, the total number of cases in the cluster is 34.
Mr Merlino said he understood how hard the latest lockdown would be on Victorians, but said "we must follow public health advice".
'If more people were vaccinated, we might be facing a very different set of circumstances than we are today.
New Zealand has already suspended its travel bubble with Victoria and while residents are now being shut out of other Australian states, prompting major airlines to slash Melbourne services.
In recent months, Australians had largely been enjoying few restrictions after the country successfully contained the spread of coronavirus, but critics say a glacial vaccine rollout has left the nation vulnerable to outbreaks from hotel quarantine facilities.
Australian Prime Minister Scott Morrison spoke to reporters this afternoon saying Victorians again faced a "challenge and a battle".
"From tomorrow morning, vaccinations at state sites will be expanded to include those in the 40 to 49-year-old age group, for the Pfizer vaccine", he said, before urging those eligible to book their jab.
Additional vaccine doses were also being sent to Victoria.