There are 90 active COVID-19 cases linked to the Casey and Dandenong local council areas in the southeast, prompting a targeted public health response.

While most of the cases have been acquired in the workplace, 34 are in the cluster of households across Clyde, Cranbourne North, Hallam and Narre Warren South.

Contact tracing has revealed household members breached the five-kilometre travel limit to visit each other.

"Five kilometres is one thing, visiting other peoples' homes is the real issue here," Premier Daniel Andrews told reporters on Friday.

"If you are breaking the rules in your home or somebody else's home, where there is no infection control, there is no formality, it is by its very nature close contact for potentially prolonged periods - all you will do is spread this virus."

Despite his disappointment, the premier indicated the families involved would not be fined.

"You need to look at the bigger picture here," he said.

"We don't want a situation where people don't have a sense of confidence and ... the sense they're obliged to tell us the full story as quickly as possible."

The first of the household cases was identified on September 4.

There is now a special team to manage the outbreak and Jeroen Weimar from the Department of Health and Human Services said authorities are in "deep and ongoing" conversations with community members and leaders.

Deputy Chief Health Officer Allan Cheng said an essential worker and both young and elderly people were among the cluster, while Fountain Gate shopping centre has been identified as a potential exposure site.

"We are not aware of any links of transmissions in that setting, but obviously we want people to come forward for testing if they are unwell," he said.

Dr Cheng said he was unaware of any link between anti-lockdown protests a few weeks ago in the Dandenong area and the rise in local cases.

Other than the household cluster in the Casey region, 56 cases include those linked to a truck manufacturer and Dandenong police station.

There are testing sites across Dandenong and Casey areas, with the latest opening on Friday at Dandenong Market.

Chief Health Officer Brett Sutton previously said the household cluster had links to the local Afghan community, but the premier stressed no group should be held responsible for outbreaks other than the individuals concerned.

"We have seen this all the way through, whether it be dinner parties from people who have been on skiing holidays in Aspen ... or families that live in the outer southeast," he said.

Victoria recorded five deaths and 45 new coronavirus cases on Friday, a significant jump after the state recorded 28 cases on Thursday - its lowest figure since June 24.

There are 920 active cases in total across the state, with just 30 of those in regional areas.

There are 90 people in hospital, including 11 in intensive care.

The state's 14-day rolling infection average continues to improve, with 42.7 for Melbourne and 2.3 for regional Victoria.

The 14-day average for cases with an unknown source has also dropped - 73 for Melbourne, none for regional areas.

The latest victims are linked to aged care and include a man in his 50s, a man in his 70s, man in his 80s and two women in their 90s.

Their deaths take the state's toll from the virus to 750 and the national figure to 837.

Australian Associated Press