NSW has reported 38 new cases of coronavirus on Thursday, with 18 new cases in isolation throughout their infectious period.
"Those numbers are too high," Premier Gladys Berejiklian said on Thursday, imploring Sydneysiders to avoid visiting family and friends.
"The saddest message out of all of that is that people with the virus are passing it on to those they love the most. We are seeing the greatest number of people get the virus in the last few days being household contacts," she said.
Today's caseload comes from nearly 40,000 tests.
Forty COVID-19 patients have now been admitted to hospital, with 11 people currently in intensive care, three of whom are ventilated. One of the people in ICU is in their 30s.
Of those hospitalised, 17 are under 55 and 10 are under the age of 35.
The premier on Wednesday announced the lockdown orders governing five million people in Sydney and its surrounds would be extended by one week - until at least 16 July.
But with the number of new cases who have spent time in the community while infectious remaining high, it may not be enough to stop the spread in some suburbs, she said.
On Thursday Ms Berejiklian said she did not want to extend the lockdown but it was up to people to respect the rules in place and restrict their movements.
"The two biggest areas where people are spreading the virus is through household contacts of people close to them, and people who are undertaking activity with symptoms," the premier said.
"These two greatest causes for where we see the rates of community transmission at the moment."
Providing care means just one person goes to support someone who might be in isolation or who might need food, essential goods or services, she said.
Ms Berejiklian has warned harsher localised restrictions could be introduced for communities in the local government areas of Fairfield, Liverpool and Canterbury-Bankstown if COVID-19 continues to spread rapidly in the area.
But Chief Health Officer Dr Kerry Chant said Sydney was now seeing cases pop up in areas not previously affected by the latest outbreak.
"Every time we leave our home, we need to consider that we may come into contact with someone who has COVID. It is therefore so critical that we minimise our movements," she said on Thursday.
New venue alerts were issued on Wednesday afternoon for Bunnings in Ashfield, a Commonwealth Bank and Woolworths at Riverwood and a Dan Murphy's in Strathfield South.
Retail venues in Marrickville, Granville, Woollahra, Fairfield, and Wetherill Park are among the new exposure sites, as are a garage in Ashfield and a petrol station in South Granville.
Dr Chant said of the 38 new cases, 26 were linked to known clusters, with 13 household contacts of previously identified cases.
She also said young people had a "great role to play" in "reaching out through their social network groups", to encourage each other to follow the rules and get tested.
The premier has said the only way to combat the highly contagious Delta variant is through high vaccination rates.
"You can't live with the Delta variance unless you have a certain proportion of job population vaccinated," she told reporters on Thursday.
Around 9 per cent of NSW residents are currently vaccinated.
Ms Berejiklian said her aim of 10 million jabs would be enough to vaccinate 62 per cent of the state's population.
Mandatory masks for teachers and senior students
Meanwhile, NSW teachers and senior students in Greater Sydney and surrounds will have to wear masks when they return to school next term.
Education Minister Sarah Mitchell said the new COVID-safe rules apply to schools inside areas impacted by the stay-at-home orders - Greater Sydney, the Blue Mountains, Central Coast, Wollongong and Shellharbour.
Masks will be mandatory for all staff in all school settings, as well as students from Year 7 upwards when on-site learning resumes on 19 July, she said on Thursday.
Ms Mitchell says she understands it's a challenging time for students, staff and parents but schools are prepared to manage the restrictions.
In regional areas, masks will be recommended for all staff in all school settings as well as high school students.
On Wednesday, Premier Gladys Berejiklian announced that when term three resumes next week, pupils in the lockdown areas would be learning from home while regional schools would have strict COVID restrictions.
Pupils who were due to return from holidays next week will mostly learn from home, but schools will be open for children of essential workers.
With AAP
