Premier Daniel Andrews confirmed Thursday’s new cases are linked to the northern suburbs outbreak, with four located in the local government area of Hume and one in Banyule.

A total of 36 people are linked to that cluster, with 16 cases remaining active.

Residents of Broadmeadows, Dallas, Preston, Roxburgh Park and West Heidelberg, including 120 people living in a social housing block, have been urged to get tested if they experience symptoms of COVID-19 after a school student tested positive.

The pupil attended East Preston Islamic College, which has been closed until further notice for deep cleaning, as contact tracing gets underway.

“We have now identified 73 close contacts at the school, predominantly students but also some teachers; they and their households have all been instructed to self-isolate and quarantine for the next 14 days,” the state’s Commander of Testing Jeroen Weimar told reporters on Thursday.

Some 400 people linked to the school are self-isolating, either at home or in accommodation and are being monitored by Austin Health and Banyule Community Health.

A further 120 residents of a housing block in Broadmeadows have been told to stay in their homes for the next 48 hours after authorities established links to a positive case.

“We are keen to test all of those people in that accommodation block to make sure we really understand any potential change of transmission,” Weimar said.

“I should stress this is an abundance of caution approach. We are taking the view that although we have every reason to believe that the positive case was contained within a particular apartment, we don’t want to take any chances.”

A close contact linked to the East Preston school has also been identified at Dallas Brooks Primary School, which has also been closed for deep cleaning as a precautionary measure.

A community door-knocking program will start on Thursday to alert residents in the suburbs about the potential exposure to coronavirus and provide information about testing sites.

A text message was sent out on Wednesday afternoon alerting people who live in or were visiting the listed suburbs to get tested.

Federal Health Minister Greg Hunt said the outbreak proved the need for vigilance.

“We are in an extraordinarily strong position but we have to be ever vigilant,” he told Nine’s Today Show.

“The NSW model has shown us that we can manage case numbers with having a predominantly open society if we have incredibly strong testing and tracing and isolation.”

Hunt said Victoria was in a strong position to manage the outbreak.

The cases, confirmed by the Department of Health and Human Services on Thursday, bring Melbourne’s 14-day rolling average to 6.1.

Victoria is poised to unveil a further easing of coronavirus restrictions on Sunday, after seven straight days with no more than five new cases.

The state’s death toll remains at 817 and the national figure is 905, with only one death in the past week.

Nine Victorians are battling the virus in hospital, though none are in intensive care.

-AAP