COVID commander Jeroen Weimar said there were 20 listed in regional Victoria, including six in Greater Geelong, five in the Mitchell Shire, one case in Bendigo and two in Ballarat.
Mr Weimar all of the regional cases - with the exception of those in the Mitchell Shire - were "reasonably linked and understood".
It comes after three people who were working at a Goornong construction site tested positive to COVID-19 on Saturday.
Those cases were connected to the V/Line contractor who returned a positive test last week..
On Sunday, Minister Martin Pakula also announced the City of Greater Bendigo and the Buloke Shire would be part of a 'vaccinated economy' trial.
Mr Pakula said the trial, which was expected to start on October 11, would involve industries like hospitality, hair and beauty, and tourism.
Under the trial, patron caps at venues and events will be expanded as all attendees will have to be fully vaccinated.
"Businesses and events are on the front line of this vital campaign to keep Victorians safe and our economy recovering strongly," Mr Pakula said.
"We'll do the work on these trials and provide businesses with the support they need to maintain and build on the gains that continue to be enabled by vaccination."
COVID-19 restrictions are also expected to ease slightly from Tuesday night as the state reaches its 80 per cent first dose target.
In regional Victoria, outdoor settings for restaurants and cafes will have their outdoor venue cap increase from 20 to 30 people.
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