The NSW Government has announced a snap state-wide lockdown which will last for at least the next seven days.

NSW Health confirmed any existing coronavirus restrictions in regional areas of NSW will now be replaced with the new public health orders matched for the entire state.

“This means the whole of New South Wales will be under stay at home restrictions from 5pm today,” NSW Health said.

NSW recorded 466 new cases of COVID-19 overnight with at least 60 infectious in the community and four deaths.

In response, Ms Berejiklian announced a series of new rules for Greater Sydney it is hoped will stem the virus spread.

Ms Berejiklian said today was “the most concerning day of the pandemic”.

The deaths included a woman in her 40s in palliative care, a man in his 70s who had pre-existing conditions, a man in his 80s, and a woman in her 70s.

The woman in her 40s and the man in his 70s were both vaccinated, while the man in his 80s was not.

The death of the woman in her 70s was only recorded recently and no other information was yet known, Ms Berejiklian said.

Meanwhile Victorian health authorities say there are very concerned as the state recorded 21 new locally acquired cases and the source of eight infections detected in the latest outbreak remains a mystery.

Health Minister Martin Foley said 11 of the new cases were in quarantine for the entirety of their infectious period and that all the new infections are linked to the current outbreak.