Victoria could be plunged into a sixth lockdown as authorities work to link fresh mystery COVID-19 cases.
Victoria has recorded another two coronavirus cases on top of the six announced earlier on Thursday.
They are family relatives of a COVID-positive man whose wife is the teacher from Al-Taqwa College who tested positive on Wednesday.
It is unknown how the couple, who live in the Hobsons Bay area and are both in their 20s, caught the virus.
Authorities are racing to trace the source of their infection and that of a man in his 20s who lives in the Maribyrnong council with a flatmate.
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He works at a warehouse in Derrimut and he and his housemate are now isolating.
The three other cases from Thursday's numbers are linked to the Moonee Valley testing site cluster.
Health Minister Martin Foley said authorities are awaiting genomic results but are working on the assumption the unlinked cases are infected with the Delta strain.
Authorities are refusing to confirm if the cases - who spent time in the community while infectious - will send the state into a sixth lockdown, less than two weeks after it emerged from its last one.
When asked about a lockdown, Premier Daniel Andrews said a series of meetings had been scheduled for Thursday afternoon.
"What I can indicate obviously is that the government's priority is to avoid what's going on in Sydney," he said at parliament.
"There's only one real way to deal with Delta outbreaks, but it's too early for us to say what will happen in relation to these cases."
The Hobsons Bay man also works at an optometrist in Caroline Springs and is a player with Newport Football Club, whose teammates and officials are now isolating.
Newport president Marwan Abou-Zeid said the player contacted the club immediately after learning of his positive result on Wednesday.
"We've stopped everything," he told AAP.
The club and Shorten Reserve, where the man played on Saturday against West Footscray, have been listed among some 20 new exposure sites.
Al-Taqwa College, a tier-one exposure site from July 28 to 30, has been closed as more than 2000 students and 300 staff get tested and self-isolate. A testing site has been set up at the school.
The coeducational, Islamic school was a significant location for transmission in last year's second wave, with at least 210 cases linked to it at the time.
Ilim College and Australian International Academy campuses as well as the Islamic College of Melbourne at Tarneit were also shut on Thursday as a precaution.
In separate letters, the three schools reassured parents that none of their students or staff had tested positive so far.
Thursday marks the one-year anniversary of Victoria recording 725 cases, the highest daily number of infections in its deadly second wave of the virus.
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