Three Hunter schools have been closed for deep cleaning and contract tracing after links to COVID cases.
Thornton, Irrawang and Mayfield West public schools did not open this morning.
Staff and students have been urged to self isolate and follow NSW Health advice.
It comes as Year 2-11 students returned to the classroom across the state.
Kindergarten, Year 1 and 12 returned last week.
Anyone who has been unwell or if you develop any symptoms such as a fever, cough, sore throat, shortness of breath, runny nose, loss of smell/taste, muscle/joint pains, diarrhoea, nausea/vomiting or extreme tiredness is being urged to get tested.