New South Wales Health is investigating a coronavirus case at a private school in Sydney.
The student is one of two new cases from more than 9,700 tests across the state in the last 24 hours.
Chief Medical Officer Dr Kerry Chant said the source of the students infection is unknown.
"Contact tracing has occurred and a number of staff, student and friends who are close contacts of the case as well as other close family contacts of the case have been identified and they have been appropriately quarantined.
"The source of that infection is unclear and those investigations are ongoing," Dr Chant said.
Saint Ignatius' College Riverview is closed while the school is extensively cleaned.
The shutdown comes as parents across the state are warned that there will be sudden school closures if students or staff test positive.
Premier Gladys Berejiklian said it shouldn't be cause for concern as an efficient system is now in place.
The other confirmed case in the reporting period is an interstate traveller who acquired the virus in Victoria.
Not one case of COVID-19 has been diagnosed in the Illawarra Shoalhaven Local Health District for a week now.
The total number of confirmed cases in the region remains at 116.
Just over 93 per cent of all local cases have now recovered while one patient is still being treated in Wollongong Hospital.
Images: NSW Health and Saint Ignatius' Riverview