Record 484 new COVID-19 cases confirmed with two further deaths overnight in Victoria

Victoria has broken its daily record for coronavirus cases with 484 confirmed overnight, taking the total number of cases in the state to 6,739.

Among the state's new cases, 97 were connected to known and contained outbreaks and 387 were under investigation.

Two more people have also lost their lives.

Premier Daniel Andrews said the numbers had not been coming down "as we would like them to".

Victoria's escalating coronavirus numbers partly come down to people not self-isolating after undertaking a COVID-19 test and not getting tested upon experiencing symptoms. An alarming new analysis conducted by the Victorian Government shows about 9 out of 10 residents did not self-isolate upon experiencing COVID-19 symptoms.

"I'm very unhappy and very sad to have to report that nearly nine in 10 - or 3400 cases - did not isolate between when they first felt sick and when they went to get a test," Mr Andrews said.

He warned the number of new cases could continue to rise.

"Unless people who get tested are staying at home and isolating until they get their test results, then we will not see those numbers come down," he said.

"They will continue to go up and up. And a six-week shutdown will not be for six weeks. It will run for much longer than that."

There are 45 aged care facilities with reported outbreaks, and about 300 positive cases in the sector overall. Mr Andrews said infections were split roughly 50-50 between workers and patients.

Premier Daniel Andrews has stressed that Victorians must wear a mask when going to the supermarket as face coverings become mandatory in metropolitan Melbourne and Mitchell Shire from midnight.

"You need to wear a mask if you're going to the supermarket and you may well be turned away if you turn up at your Coles or Woolies or IGA and you don't have a mask on," he said.

Mr Andrews said the state would be in a "much longer" lockdown than six weeks if its "stark" coronavirus numbers did not begin to plummet.