NSW has recorded seven new virus cases as a COVID-19 cluster in Sydney's CBD grew to 28 infections after two more members of a city gym tested positive.
Of the seven new cases diagnosed overnight on Sunday, five are linked to the fitness hotspot including a close contact of a prior diagnosed member.
One new case is among returned travellers in hotel quarantine while a student at a western Sydney high school has also tested positive.
St Paul's Catholic College in Greystanes will be closed on Monday for cleaning, NSW Health said on Sunday.
People who attended the City Tattersalls gym in the Sydney CBD between 8am and 2pm on August 19, 21, 23, 24 and 25 are now considered close contacts and must isolate themselves and get tested immediately.
Authorities are also investigating the source of an infection acquired by a staff member at the Surry Hills Police Cells Complex.
NSW deputy chief health officer Jeremy McAnulty said the Justice Health and Forensic Mental Health Network were taking appropriate health and safety measures.
"Contact tracing has been undertaken and the staff member is isolating."
There were 19,626 tests conducted cross NSW in the 24-hour reporting period to 8pm Saturday, compared with 24,632 on Friday, NSW Health said.
A further 12 locations, including several public transport routes and Virgin Active gyms on Pitt and Margaret Streets in the CBD, have been added to a list of locations visited by people with active infections.
A homewares shop, House, at Broadway shopping centre was also closed on Sunday after a customer with COVID-19 went to the store on August 24, around 2pm.
Anyone who visited the above locations are being urged to watch for symptoms.
As a precaution, people who live or work in the Greater Sydney metropolitan area and Central Coast are advised to refrain from visiting aged care facilities until September 12.
The preventative measure to keep the virus from infiltrating nursing homes and affecting the vulnerable elderly residents will mean many will be denied a visit on Father's Day.
Meanwhile, three Sydney schools that closed on Friday after staff members contracted the virus will reopen on Monday.
They include Homebush Public School, Double Bay Public School and Ryde Secondary College.
There are 66 active COVID-19 cases in the state, including six who are in intensive care, of whom three are on ventilators.
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