Victoria has recorded five new locally acquired Covid-19 cases as Melburnians face their second weekend in lockdown.
The Department of Health confirmed the increase on Saturday morning, which takes the state's community cases since the outbreak occurred to 70. One of those cases has since recovered.
It is unclear if the new cases are linked to current cases, with an update from the state government expected later on Saturday.
Daily cases have increased over two consecutive days despite lower testing numbers.
There were more than 36,000 tests performed in the previous 24-hour reporting period.
Source of 'disturbing' outbreak not yet found
Health authorities are scrambling to find the source of a new, highly-infectious strain identified in seven people including three children. Among that group are a family who travelled to NSW for a camping trip.
The family has more than 300 close contacts, many of them at North Melbourne Primary School, and authorities suspect there has been transmission between two grade five students at the school.
Genomic sequencing has failed to link the variant to any case in hotel quarantine.
The Delta variant, also known as B.1.617.2, has wreaked havoc in India and is also now the dominant strain in the UK.
Chief Health Officer Brett Sutton described the discovery as "disturbing news".
While the Delta variant has been found previously in Australian hotel quarantine, this is the first time it has emerged in community cases.
Deputy Chief Health Officer Allen Cheng said the other Indian variant, Kappa, circulating in Melbourne is probably 50 per cent more infectious than the strain that forced the city into a prolonged lockdown last year.
Two cases linked to suspected "fleeting" transmission, which was used to justify the extension, were reclassified as false positives on Thursday evening.
Authorities initially thought a woman caught the virus at a Metricon display home and believed a man may have picked up COVID-19 at Brighton Beach Hotel.
That was not the case, with an expert panel review determining neither is infected with coronavirus.
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