New South Wales will revert to tighter coronavirus restrictions for homes and venues in the Greater Sydney region after the state recorded another 30 cases by Sunday morning.

The state government is also “asking” people across Sydney to wear masks in public for the next few weeks, especially indoors, but has not yet made that measure mandatory.

The growing Northern Beaches cluster has prompted Victorian Premier Daniel Andrews to effectively close the state’s border to Greater Sydney, giving Victorians until Monday to get home – or otherwise face two weeks hotel quarantine. South Australia, too, is closing its border to Sydney.

Premier Gladys Berejiklian said 28 of Sunday’s new cases had been directly linked to the Avalon cluster, with two still under investigation.

“We have not seen massive seeding outside the Northern Beaches,” Ms Berejiklian said at a press conference.

The latest diagnosed cases lift the state’s tally of known infections to 70.

But new rules have been clamped on Greater Sydney, the Blue Mountains and Central Coast, to nip the spread of the current Northern Beaches cluster.

NSW recorded 30 new locally acquired cases of COVID-19 in the 24 hours to 8pm last night.

Six cases were reported in overseas travellers. This brings the total number of cases in NSW since the start of the pandemic to 4,559. pic.twitter.com/wHkwBXgAz7

— NSW Health (@NSWHealth) December 20, 2020

Public health orders will limit households to only welcoming 10 visitors per day,  while hospitality venues will revert to density limits of one person per four square metres.

Limits will also be placed on public activities.

Dancing will not be permitted in public, except for no more than 20 people at weddings. Singing and chanting will also be banned, except for places of worship allowed to have five people doing that activity.

Those rules are currently in place on a wait-and-see basis until Wednesday, December 23.

Ms Berejiklian said those rules would be reassessed on Wednesday, and potentially extended if needed.

NSW chief health officer Dr Kerry Chant. Photo: AAP

“If we continue to work together and see things improved, obviously we will be able to reassess these settings moving forward,” she said.

“I will confirm that the health experts and others will advise government on Wednesday morning as to these settings and what we do, post the current designated lockdown period.”

The state government is under pressure to extend rules to make masks mandatory in public areas, but has so far resisted that change. However, health minister Brad Hazzard said “it would make a lot of sense for people to be wearing masks at the present time.”

“We appreciate there are some people who cannot wear masks for various health reasons, but certainly I am asking and the government is asking all residents of the Greater Sydney area to wear masks at least for the next few days until we revisit this issue on Wednesday,” he said.

“It may well be wise to wear those masks going through Christmas, New Year in the Greater Sydney area.”

Premier Berejiklian also asked people not to panic-buy supplies from shops, saying essential stores would remain open.

“Even if you live beyond the Northern Beaches, you should be wearing a mask indoors,” she said.

The Premier also asked people going grocery shopping, visiting a place of worship, or in “an indoor setting or anywhere where social distancing can’t be maintained, please wear a mask”.

“And, for heaven’s sake, do not get on public transport unless you are wearing a mask. I can’t stress that enough,” she added.

The list of at-risk venues now extends up to the NSW north coast town of Forster, out to the western Sydney suburb of Homebush, and into the heart of the city in Surry Hills.

Daniel Andrews announced new restrictions on NSW visitors. Photo: Facebook

Just days out from Christmas, the sudden outbreak has derailed countless holiday plans as people are forced into quarantine or state premiers throw up new border restrictions to those coming from NSW.

South Australian Premier Steven Marshall said his state would mandate 14 days hotel quarantine for those coming from Greater Sydney, and get COVID tested twice during their stay. People from the Northern Beaches will be blocked entirely.

All arrivals from NSW will be required to get a test on arrival into SA. NSW visitors from outside Greater Sydney will not have to quarantine, but will still have to get tested when entering SA.

VIC Premier Andrews announced soon after the NSW press conference that his state would put up a “hard border” to its northern neighbour. He said the entire Greater Sydney area would be declared a “red zone” from 11.59pm Sunday, meaning visitors to VIC would not be allowed entry without two weeks quarantine.

“All of those in Greater Sydney and the Central Coast, please do not come here,” Mr Andrews said.

“You must stay in your state to keep Victorians safe and play your part in a national COVID-19 policy response. This is a national system working as it should.”

The Premier said this would be the case for visitors, but that returning Victorian citizens would get an extra 24 hours, until Monday 11.59pm, to get home before having to enter hotel quarantine. He also pleaded with Victorians to not go to Sydney, saying they would face quarantine on return.

Mr Andrews could not comment on when those rules may be relaxed, but that it would extend far beyond Wednesday.

“We have built something precious and we intend to safeguard it,” he said.