Dr Kerry Chant said the new cases include a man in his 40s and a man in his 20s. The third case, another man in his 20s, is a close household contact of one of those cases.
There were also two cases acquired overseas, who are now in hotel quarantine.
There were 32,010 tests reported to 8pm last night, compared with the previous day’s total of 27,894.
Dr Chant also revealed genomic testing has shown the Croydon cluster and the Avalon cluster are linked.
"Investigations have revealed that a case from the Croydon cluster and a case from the Wollongong cluster both attended The Swallowed Anchor restaurant in Wollongong on 19 December. So last night we put out an urgent public health alert and contacted a number of people at that restaurant," she said.
Premier Gladys Berejiklian flagged she would make an announcement on Saturday regarding residents in the southern zone of the Northern Beaches.
There were no new infections linked to the Avalon cluster, which has 146 cases.
It comes as Victoria has announced a border closure with the whole of NSW, which will come into effect from 11.59pm 1 January, 2021.
Anyone who arrives back in Victoria from anywhere in NSW after that time will have to go into isolation for 14 days.
Victoria closes border with NSW over new COVID-19 cluster
Acting Victorian Premier Jacinta Allan said tens of thousands may be impacted by Victoria's decision to close its border to all of NSW.
"It does cause disruption to peoples' travel plans, holiday plans and that is going to be difficult for those families, working through that.
"But it is a decision based on the public health advice, based on the case numbers coming out of New South Wales, also [it is also] based on wanting to make sure we lock in the precious gains and sacrifices Victorians have made over 2020."
Victoria recorded five cases of COVID-19 on Thursday. No additional cases were announced on Friday morning.
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If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080.
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