Police on horseback patrol a mass vaccination centre against anti-vaccination protesters in Melbourne Photograph:( AFP )
New South Wales and Queensland were put on COVID-19 alert after reports indicated a woman and her husband travelled from Victoria to New South Wales and Queensland.
As authorities in Melbourne gave the green signal to the city to end the lockdown, four new local coronavirus cases were detected on Thursday.
City officials have made wearing masks mandatory outside "in all circumstances" as Victoria reported new cases from a single house even as authorities have insisted on increased testing.
Health officials are still reportedly trying to find out how the Delta strain spread in the community in Melbourne. The lockdown will end in Melbourne at the stroke of midnight.
Victoria state acting premier James Merlino however cautioned that "until we have widespread vaccination across Victoria and across our country, the virus will still be with us."
Meanwhile, New South Wales and Queensland were put on COVID-19 alert after reports indicated a woman and her husband travelled from Victoria to New South Wales and Queensland.
The officials have been trying to map the couple's footprints in order to locate the likely Covid hotspots. However, Queensland's state health minister Yvette D'Ath said that the couple were likely at the end of their infection cycle even though may face criminal charges for breaching coronavirus border restrictions.
New South Wales has reportedly not registered a single COVID-19 case and Queensland reported a case in March.
Australia has largely controlled the pandemic since last year with just over 30,000 cases and 910 fatalities, however, the recent surge in late May worried officials amid a slow vaccination drive leading to another lockdown in Victoria state.
The country has tightly controlled its borders not allowing tourists to enter and had even kept out citizens since last year allowing only visitors from New Zealand recently which has successfully fought the virus.
Despite criticism, PM Scott Morrison said the rules will apply into next year.
(With inputs from Agencies)