A local bottle shop is at the heart of anxiety about Sydney's latest cluster of COVID-19 cases.
BWS in west-suburban Berala has been identified by authorities as the site of a number of virus transmissions after brief interactions.
A high health alert for the venue now stretches between December 22 and New Year's Eve, skipping only Christmas Day.
Most who dropped by the bottle-o across the Christmas period are now considered close contacts and need to isolate for 14 days even if they only attended the outlet for a short time.
What's more, close contacts will have to isolate until each patron receives a negative result.
Tens of thousands of Sydneysiders will be impacted, with 1000 people visiting the store to stock up on alcohol on Christmas Eve alone.
Authorities will be nervously waiting to see how far the virus has spread beyond the takeaway.
The Berala cluster now numbers 13 cases, with five recorded in the 24 hours to 8pm Saturday.
"I can't stress enough how concerned we are about the transmission potential," NSW Chief Health Officer Kerry Chant said on Sunday.
There were eight locally-acquired cases in total recorded in the state in that period, from 18,923 tests.
Genomic sequencing reveals the cluster in western and southwest Sydney is not linked to the so-called Avalon cluster.
Instead, the source is a patient transport worker who took a family returned from overseas to a health facility. The worker was infected and passed the virus on to a colleague.
The colleague then attended the Berala bottle shop on December 20 for a "very fleeting amount of time" and passed the virus on there.
Other transmission events occurred there from apparently brief exposures, meaning there is an "elevated risk", Dr Chant said.
The government has set a target of 20,000 or 30,000 tests a day.
Health Minister Brad Hazzard has encouraged residents, particularly in the Cumberland and Wollongong areas, to "rise to the occasion again".
"Clearly we have some major concerns in relation to the number of people who may have been exposed in the area around Berala," he said.
Two of the new cases are household contacts of cases in the Avalon cluster, taking it to 148 cases. The other case is a household contact of a previously reported case in Wollongong.
Meanwhile, new rules mandating masks in indoor settings in greater Sydney will be enforceable with a $200 fine from midnight.
Mr Hazzard said he has asked police to exercise discretion.
Masks are now mandatory in shopping centres, on public transport, in places of worship, hair and beauty premises, entertainment venues such as cinemas and other indoor venues like post offices and banks.
All hospitality staff are also required to wear one.
Children under 12 and those with specific health disorders are exempt but should wear masks where possible.
Stay-at-home orders continue for northern beaches residents north of Narrabeen Bridge until at least January 9. The southern half of the peninsula now has the same restrictions as the rest of Sydney.
Restrictions on businesses and gatherings include gym classes reduced to 30 people and places of worship and funerals to one person per four square metres, and up to a maximum of 100 people per separate area.
Outdoor performances and protests are reduced to 500 people and controlled outdoor seated events to 2000.
The NSW government has defended allowing the Australia-India Test match to go ahead next week the SCG. At least 20,000 people are expected to attend daily.
© AAP 2021