All people on Sydney's Northern Beaches - a population of around 250,000 people - have been urged to self-isolate after a COVID-19 cluster in the area increased to 28 cases on Friday.
NSW Premier Gladys Berejiklian announced an additional 10 COVID-19 cases on Friday morning. She said one other person who contracted the virus in Sydney travelled to Queensland but had since returned to NSW, bringing the total number of those affected to 28.
Fifteen new cases were identified on Thursday, with health authorities urging locals from the Spit Bridge to Palm Beach to lockdown by staying at home as much as possible over the next three days.
Watch: NSW Premier Gladys Berejiklian on the importance of following guidelines. Post continues below video.
NSW Health says residents should not visit hospitals and aged care facilities unless essential, work from home, avoid unnecessary gatherings, keep to their household groups, and avoid high-risk venues like gyms.
People should avoid unnecessary travel to the Northern Beaches and people living there should avoid leaving.
Her government is imploring Sydneysiders to wear masks, especially on public transport and in indoor areas where social distancing is difficult.
Here is everything we know so far.
The current cases.
Authorities are investigating a potential super-spreader event at a local RSL, Chief Health Officer Kerry Chant said.
Health authorities detailed three new cases on Thursday morning - a woman in her 50s who works at Pittwater Palms aged care facility at Avalon Beach, her partner and a Frenchs Forest man in his 60s who plays the drums for a local band.
Dr Chant said her department's hypothesis was that an unknown person infected the drummer, a woman in her 60s and man in his 70s at Avalon RSL last Friday where the band was performing.