Victoria has recorded highest number of deaths overnight amid Seven arrested at anti-mask protest in Melbourne

Victoria has recorded 394 new coronavirus cases and 17 deaths overnight — the highest number of people to die in a single day in Australia since the pandemic began.

The people who died were two men in their 50s, four men in their 70s, four women and two men in their 80s, and two women and three men in their 90s.

Australia's previous highest daily death toll was 15 deaths, recorded just four days ago on August 5.

Premier Daniel Andrews has labelled COVID-19 a "wicked, silent enemy", warning Victorians they will have no chance of driving down case numbers without the state's tough restrictions.

“These are heartbreaking decisions to make. These are very challenging settings to put in place. But unless we do this, this second wave will not end anytime soon,” he said.

“If we don’t limit movement, if they don’t follow the rules, we, as a state, have zero chance of driving down these numbers. It won’t happen by accident. It won’t happen because of good fortune. It won’t happen because of the passage of time. We need to make these decisions.”

The number of confirmed cases of community transmission without a known source has grown by 174 overnight to a total of 2,758.

Mr Andrews described those "mystery cases" as the state's "biggest challenge".

A total of 634 people are in hospital with Covid-19, 43 people are receiving intensive care, and 26 people are on ventilators.

Meanwhile Police arrested seven people and issued 27 fines to protesters who attended an anti-mask and anti-lockdown rally in Melbourne's CBD today.

Six people were arrested after refusing to provide their details to police.

They were released from custody after providing their details, with each person fined $1652.

Twenty-four of the fines issued were for breaching restrictions that state residents must not leave home without an essential reason.