The state has recorded 78 new Covid-19 cases overnight in the 24 hours to 8pm
Ms Berejiklian warned residents they could be carrying virus with no symptoms
Positive results came from 63,000 tests; higher testing rates in the Fairfield LGA
High rates of transmission also detected in Hurstville and Kogarah in city s south
Greater Sydney is now into its fourth week of strict stay-at-home lockdown rules
New South Wales has recorded 98 local cases of Covid-19 overnight - including 37 unlinked infections - as Premier Gladys Berejiklian warned Sydneysiders to stay at home to slow the spread of infections.
Of the newly-acquired cases, 20 were active in the community for their entire contagious period and another 17 for part of the time they were infectious.
In a worrying sign the city s outbreak of the highly-contagious Delta variant is still spiralling out of control, NSW Health said 37 of the cases have not yet been linked to known cases.
Ms Berejiklian said 67 infections - more than two-thirds of the new cases - were found in Sydney s south-west.
Victoria Premier Dan Andrews has warned he s set to tighten travel restrictions even further as the border with New South Wales looks set to stay firmly shut indefinitely.
The state branded NSW a red zone ahead of last week s snap five-day lockdown after a team of Sydney removalists brought the deadly Delta variant of Covid to Victoria.
The border closure currently means anyone now arriving from NSW must apply for an exemption before they are allowed entry into the state.
But as the Victoria lockdown was extended on Monday after the state recorded 16 new Covid-19 cases, Mr Andrews hinted at even tougher measures ahead.