A coronavirus outbreak in Sydney's eastern suburbs has grown to three, after a woman in her 70s was exposed to COVID-19 at a cafe.
NSW is once again on high alert after two new locally-transmitted were detected on Wednesday and a number of busy venues were declared potential exposure sites.
The third person - the woman in her 70s - tested positive after visiting one of those sites, the Bell Cafe in Vaucluse.
Additionally, a man in his 40s has tested positive in the Baulkham Hills area.
But NSW Chief Health Officer Kerry Chant Health cautioned this might be a false positive or an old case "as the viral load in his system was very low".
"On that basis, it could be a false positive or it could be an old case," she told reporters on Thursday.
The alarm about the latest outbreak began on Wednesday night when NSW Health discovered a man in his 60s and his wife had tested positive for COVID-19.
The Bondi man works as a driver and had transported international flight crews.
The exact source of his infection is unknown and but Dr Chant said the man's viral sequencing results matched the highly contagious Delta variant circulating in the US.
NSW Premier Gladys Berejiklian said the confirmed local cases - the first since early May - were a reminder of the need to be vigilant.
"We've been through this before. We can't be complacent," she said.
"We know that two can become 20 very quickly."
Extra pop-up testing clinics have been set up in eastern Sydney and the premier is urging people in areas the two cases visited to get tested.
The man visited a string of venues while potentially infectious, including Events Cinema at Bondi Junction for a screening of The Hitman's Wife's Bodyguard on Sunday.
Other potential exposure sites include Myer and David Jones in Bondi Junction, cafes in Vaucluse and North Ryde, a car wash in Redfern and a fruit and vegetable shop in Zetland.
More than a dozen close contact venues have been identified across Sydney.
The two cases could mean NSW reintroduces some restrictions ahead of the school holidays which begin on June 26.
Public health alerts were also issued last week for venues in the towns of Moree, Forbes, Dubbo and Coonabarabran after an infected couple from Melbourne drove through on their way to Queensland.
The WA and Tasmanian governments have told anyone who has recently returned from NSW to check the list of exposure sites and get tested and isolate if they have been to any of those venues.
Investigations are also underway into a potential hotel quarantine breach at Sydney's Radisson Blu hotel.
Meanwhile, NSW Health says it administered a record 17,223 COVID-19 vaccines in the 24 hours to 8pm on Tuesday, including 6048 at the vaccination centre at Sydney Olympic Park.
The total number of COVID-19 vaccines administered in NSW is now 1,737,557.