Victoria has posted 1061 new locally acquired COVID-19 cases amid strict new rules for people arriving from southern Africa in response to concerns over the heavily mutated Omicron variant.
The state has also recorded four more virus-related deaths.
Victoria continues to manage more than 11,330 active coronavirus cases. There are 283 COVID patients in the state's hospitals, 44 of them in intensive care and 20 requiring ventilation.
Health authorities say virus testers managed to process almost 53,000 results in the 24 hours to Saturday evening.
Victoria, meanwhile, will send all international arrivals into home quarantine for 72 hours following the international emergence of Omicron.
It has not been detected in Victoria, but the state's chief health officer Brett Sutton says precautionary measures are necessary so authorities can gauge the health response required by the new variant.
Key questions about Omicron's transmissibility, whether it results in milder or more serious illness and the effectiveness of vaccines are yet to be answered.
"It certainly seems to have spread very quickly in southern Africa," he said on Sunday.
"It is likely to be a very transmissible variant but we will have greater clarity on that in coming days and weeks."
As case numbers increase in southern Africa, hospitalisations will help show how serious the variant is, and Dr Sutton said there had already been cases of vaccinated and previously infected people contracting Omicron.
"But that's true for Delta as well, so we really do need a few more weeks to understand," he said.
"So it is sensible for us to take that precautionary ... and hopefully temporary approach as many other countries around the world have done."
New arrivals to the state who have recently been in one of nine southern African countries must now quarantine in a hotel for 14 days, under federal government rules.
Those countries are Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa, The Seychelles, and Zimbabwe.
Anyone already in Victoria who's been to those countries in the past 14 days must also be tested and isolate for two weeks.
Victoria's health department says only a "very small" number of people are in that category.
The three-day home quarantine requirement for international arrivals is in line with changes announced by NSW and the ACT overnight.
The Victorian government is warning the orders may be extended.
Victoria is 90 per cent fully vaccinated for everyone aged 12 or older. It recorded 1252 COVID-19 cases and five deaths from the virus on Saturday.
Australian Associated Press