Australia's most populous state has announced new restrictions for the Greater Sydney area in an attempt to contain a growing outbreak of Covid-19.
Household gatherings will be capped at 10 people and hospitality venues at 300 until Wednesday. Residents had already been told to stay at home, reports BBC.
The cases were found in the city's Northern Beaches area, which entered a five-day lockdown on Saturday.
Since then Sydney residents have rushed to leave the city ahead of Christmas.
Thousands have travelled from the city in New South Wales (NSW) to the neighbouring state of Victoria.
In response, Victoria announced that its borders would be closed to residents of Greater Sydney and the NSW Central Coast from midnight.
The outbreak has also forced organisers of the Sydney to Hobart yacht race to cancel the event for the first time in its history.
The restrictions in Greater Sydney - including the Central Coast and Blue Mountains - can be lifted if no cases of community transmission are reported. Other measures include:
• The rule of one person per 4 sq m (43 sq ft) will return for all indoor settings including hospitality venues and places of worship
• A cap of 300 people will be introduced in those places
• Singing and chanting at indoor venues will not be allowed
• Dance floors will not be permitted, apart from weddings when up to 20 people from the bridal party will be allowed
Speaking at a news conference, NSW Premier Gladys Berejiklian urged people in the Sydney area to wear face masks in public although it was not mandatory. Earlier she pleaded with all residents to limit their activities over the next few days and stay home "unless you really have to" go out.
The new cluster emerged just days before the Christmas period, prompting concern that travel restrictions may impact festive plans.
Until Wednesday, Australia had recorded just one locally transmitted infection in the past fortnight. The country, which is considered a relative success story of the pandemic, has recorded about 28,000 infections and 908 deaths in total, according to a Johns Hopkins University tally.
Meanwhile, the more than 250,000 people who live in Sydney's Northern Beaches have been banned from leaving their homes except for work, exercise, essential shopping and compassionate reasons until Wednesday.
Those living in other parts of Sydney have been told to avoid the area.
The NSW government has urged all locals to wear masks in public areas like supermarkets and churches and to be on "high alert".
The next five days has been described as a "tipping point" by epidemiologist Mary-Louise McLaws.
"We can only hope that it remains focused in the Northern Beaches, but if it goes across all of Australian than we will need more tightening," she said.
Where did the outbreak come from?
Sydney's Northern Beaches outbreak grew to 68 cases on Sunday, with 30 new cases recorded in the previous 24 hours.
Tests have shown that the outbreak is similar to a strain of Covid-19 found recently in quarantined travellers, state officials said.
But authorities still do not know how it got into the community.
They said it had spread after one couple failed to isolate at home while awaiting coronavirus test results.
Their 11 December visit to a popular lawn bowls club and pub in the Northern Beaches suburb of Avalon has now been identified as the "super spreader" event.
However, it is unclear how the couple - who had not travelled overseas - became infected.
Since Australia closed its borders in March, its outbreaks have largely begun with breaches in its hotel quarantine system for returned international travellers.
Such instances led to Australia's biggest outbreak in Melbourne.