COVID-19 cases have skyrocketed across Sunraysia with 45 new cases detected in the region at the weekend.

The tally takes the number of current active cases to 67, while regions across the border prepare to enjoy new freedoms.

Victorian health authorities said they were "particularly concerned" about the rising number of cases in the Mildura region which rose to 55 on Sunday with 20 new cases reported on Saturday and another 18 yesterday.

There were an additional seven new cases reported in Dareton over the weekend.

COVID-19 response commander Jeroen Weimar said on Sunday the community response to the latest outbreak in Mildura had been "extraordinary".

"It's been a really busy couple of days (and) we thank the support of the community across Mildura," Mr Weimar said.

"Obviously we put it into lockdown late on Friday night, but we have seen an extraordinary response over the last couple of days," he said.

Mr Weimar said more than 1000 people were tested on Saturday across a number of different testing locations across Mildura.

"Again, we've seen a really strong community response," he said.

"We'll, of course, continue to work with the community across Mildura to get to the bottom of those cases.

"The ones we have seen in the last 24 hours appear to be very closely linked to a number of known households and movements, but there is also some cross-border issues into communities moving into New South Wales."

Health Department deputy secretary Kate Matson warned said there may be additional cases in the community that were yet to be found.

"The next seven days will be crucial for us to have a really stringent public health response," she said.

Victoria's Chief Health Officer Brett Sutton urged Mildura residents to get vaccinated, look out for symptoms and get tested if any develop, with a rapid response testing team sent to the region for support.

"We've seen regional communities get through an outbreak so we know it can be done – it's vital we protect the local community and the rest of regional Victoria from significant outbreaks," Professor Sutton said.

Mildura is under the same stay-at-home rules as Melbourne, excluding the curfew, with a 15km travel limit and visitors banned from entering people's homes.

More than 86 per cent of Mildura's eligible population have had one dose of a COVID vaccine, and 51 per cent have had two doses.

The emerging crisis prompted NSW Health to establish emergency accommodation in Wentworth to help close contacts of people with COVID-19 to isolate safely and effectively if they could not do so at home.

Of the seven new cases in Dareton, which took the town's total number of active cases to 12, four were household contacts and three were being investigated.

A number of casual contact venues on the NSW side of the border were released at the weekend. They were Shell Buronga (Sunday, October 3, 11.10am to 11.15am); Dareton Mini-Mart (Wednesday, October 6, 3pm to 4pm); and IGA Dareton Plus Liquor (Thursday, October 7, 12.40pm to 12.50pm and Friday, October 8, 7.10am to 7.20am).

Anyone who visited the venues on the specified dates and times listed is a casual contact unless they have been contacted by NSW Health as a close contact and must get tested and isolate until a negative test result is received.

The Victorian Department of Health and Human Services said it regularly managed exposure sites that it did not publish online, particularly if the sites represented lower-risk exposure, if they had comprehensive record-keeping and contact-tracing measures, or if they identified small, private locations.

Late on Sunday two Mildura tier 1 exposure sites were listed on the www.coronavirus.vic.gov.au web page.

Davo's General Store & Take-Away, 285 San Mateo Avenue, was listed as an exposure site on Monday, October 4, between 2.30 and 3.20pm. A person who later tested positive visited the store.

Chloe's Nails and Beauty, 210 Deakin Avenue, was an exposure site on Saturday, October 2, between 10am and 12.10pm. A person who later tested positive visited the store. 

People who were at either place at the relevant times should get tested for COVID-19 and self-isolate for 14 days from the date of exposure.