The latest cases of community transmission in Victoria are two people linked to a bayside Thai restaurant who then travelled to NSW. The pair is not yet counted in official daily numbers for Victoria.

The Victorian government sent out a statement on Friday saying they attended the Buffalo Smile Thai restaurant on December 21.

They travelled to Lakes Entrance a week later on December 28 and 29, then went on to Bega and Bermagui in NSW.

Victorian public health authorities contacted them on December 31, where they were already in a NSW COVID-19 testing line, a spokeswoman said. They are now isolating in Victoria.

Apart from these two cases revealed on Friday, another eight Victorian cases are linked to the Black Rock restaurant.

"We now have two separate groups of people who are unknown to each other who were adjacent with each other in the restaurant," Victorian testing manager Jeroen Weimar said.

A NSW returned traveller was also at that restaurant.

Health Minister Martin Foley said that was the primary line of investigation for the outbreak.

No link has been found between the eight cases and any other known infections and genomic testing is underway to confirm if the traveller is the root of the outbreak.

Mr Weimar said 170 primary contacts of those eight cases are the major concern, and hundreds of secondary contacts are also being asked to get tested and self-isolate for 14 days.

"If your primary close contact connection turns out not to have been infectious you will be released from that investigation and you are free to go," he said.

One of the positive cases recently moved to a holiday rental at Leongatha in the state's east, widening the area of close contacts.

"Do not think this is just a Bayside suburbs, Mitcham issue. This is not only a Melbourne issue, this is a Victorian issue," he said.

Five exposure sites are among those authorities are most concerned about, including the Thai restaurant.

Royal Brighton Yacht Club, Holy Family Parish Catholic Church in Doveton, the clubhouse bar at Woodlands Golf Club in Mordialloc and the Village Cinema at Century City in Glen Waverley are also areas of concern.

The state is handling another nine active cases in overseas travellers who are in hotel quarantine.

Victorians holidaying in NSW have been racing to cross back into their home state since the 'hard' border closure was announced for Friday night.

Motorists are facing lengthy queues to enter from NSW as a quarantine deadline looms.

The influx is leading to high demand at coronavirus testing sites as travellers face mandatory testing.

Health authorities have boosted testing sites with greater capacity and longer opening hours.

Growing coronavirus case numbers in NSW on Thursday prompted Victorian authorities to impose a hard border from midnight Friday. Anyone arriving after that time from any part of NSW must spend a fortnight in quarantine.

Mr Weimar said anyone who is already in line for the border when the hard restriction border comes into force at 11.59pm on Friday will still be allowed to isolate at home.

But those who come after the deadline must quarantine in a hotel for 14 days.

On Thursday acting premier Jacinta Allan reintroduced the mandatory masks requirement for indoors and reduced the number of visitors allowed in Victorian homes down to 15 from 30.

Victorians can continue to return from Canberra with a permit, while more details will be announced for border communities and people who are travelling through NSW to return to Victoria.

Australian Associated Press