Another school student and five returned travellers make up six new cases of coronavirus in NSW.
The case involving a twelve-year-old student at Camden High School is under investigation.
Close contacts are being contacted and isolated and the school is closed for a deep clean.
The other five cases are in hotel quarantine.
Yesterday, four new cases were advised - a student at Lane Cove West Public School and three returned travellers.
The latest figures, for the 24 hours up until 8pm on Thursday, include 15,278 tests, compared with 17,175 tests in the previous 24 hours.
More than 780,000 COVID-19 tests have been carried out in NSW.
NSW Health re-issued advice not to travel to Melbourne "hot spots" and continues to urge anyone feeling unwell - even with the mildest of symptoms such as a runny nose or scratchy throat - to practice good hygiene by coughing and sneezing into their elbow or a tissue, washing their hands regularly, isolate themselves from others and to seek testing via their GP or by visiting one of the COVID-19 testing clinics.