Of of the new cases on Sunday, one is a returned traveller in hotel quarantine, four were from routine testing, 53 are still under investigation and 16 have been linked to outbreaks.

The Saturday spike resulted in Premier Daniel Andrews announcing a lockdown of nine inner-Melbourne public housing blocks and more areas being added to the COVID-19 "hot zone".

As of Saturday Ballarat remained without an active COVID-19 case.

A total of 27 cases have now been detected in the North Melbourne and Flemington towers.

The drastic measures were taken to quell a cluster of up to 30 cases in public housing towers, by shutting down nine buildings affecting 3000 people.

Police are guarding every entrance of the housing estates and residents are not allowed to leave their homes for any reason.

The premier announced additional resources for residents of the buildings, including a hardship payment and additional health services including more testers.

The 3000 will have their rent waived for the next fortnight and will receive hardship payments, Mr Andrews told reporters on Sunday.

He said those employed would receive a $1500 hardship payment, while those not in the workforce will receive $750.

The government said it would arrange the delivery of food and medical supplies to all homes.

The premier said the hard lockdown was about safety for residents and the wider state.

"This is about protection for you and your loved ones.

"And then, by extension, it's about protecting the entire state and we don't make those decisions lightly," he said.

Postcodes 3031 and 3051 have joined the 10 other community transmission "hot zones" under stay-at-home orders.

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