A Sydney high school and a Catholic primary school have been closed for cleaning after a staff member and a student were diagnosed with coronavirus.
The NSW Education Department says Ryde Secondary College, in the city's northwest, will be closed after a staff member tested positive for COVID-19.
Staff and around 1000 students at the co-educational school have been asked to stay home while the contact tracing process begins and the school is deep cleaned.
"All staff and students are asked to self-isolate while contact tracing occurs," the department said on Friday.
St Gertrude's in Sydney's west is also closed on Friday after a student was diagnosed.
A spokeswoman said the school had around 650 students from Kindergarten to Year 6, and 50 staff who have been advised to isolate at home and monitor for symptoms.
Riverstone High School, Wyndham College and Schofields Public School will reopen on Friday.
Meanwhile COVID has closed a swathe of venues in Sydney's north from Manly to the Central Coast.
There were nine new cases in the state in the 24 hours to 8pm on Wednesday from more than 30,000 tests, with all cases locally acquired from known sources.
NSW Health's Jeremy McAnulty issued alerts for a number of new venues including six in Sydney's north: Harris Farm in Willoughby on August 22, Hunters Hill Bowling Club on August 23, 4Pines Manly on August 23, Magpies Waitara on August 24, Hornsby PRP Diagnostic Imaging on August 24 and Fitness First gym at Balgowlah.
Holy Name Catholic Church at Wahroonga has also shut as a precaution, after a parishioner who attended church on Sunday August 23 tested positive.
Churchgoers who attended the same service are considered casual contacts and must isolate and get tested if even the mildest symptoms present.
Meanwhile a cluster at a gym in Sydney's CBD has grown from three to eight people.
NSW Health says anyone who attended the City Tattersalls Club gym between 8am and 2pm on August 19, 21 or 23 should get tested and isolate at home for 14 days.
The club is now closed for cleaning.
An alert was also issued for those who attended a dance class on Monday evening at Virgin Gym in Zetland in Sydney's east, and the Bond Street Fitness First gym where a COVID-positive person visited on August 21 and 22.
People who visited Destro's Pharmacy at Drummoyne in the inner west on August 22 are also advised to watch for symptoms.
Two new cases who will be included in Friday's numbers also visited public places while infectious.
A man worked at David Jones Elizabeth St food court while infectious but did not have contact with the public, while another person commuted by train from Woy Woy on August 24 and 25.
Those on the same trains are considered casual contacts.
"While case numbers have remained low in the past two weeks, the virus continues to circulate in the community and we must all be vigilant," Dr McAnulty said in a statement on Thursday.
There are six COVID-19 patients in NSW in intensive care, with four ventilated.
© AAP 2020