South Australian secondary students will be required to wear masks in schools for another month to try to minimise COVID-19 infections.
The state's Emergency Management Council met on Tuesday and decided to keep mask use in place for the first four weeks of term two starting next week.
Primary school students will not be obliged to wear masks but it will be strongly recommended.
All teachers, in both primary and high schools, will be required to wear masks.
Premier Peter Malinauaskas said the decision to keep masks in place for high schools, weeks after dropping more widespread mask use, was a difficult one.
Education Minister Blair Boyer said it came after SA schools suffered probably the most disruption during term one of any state.
A number of schools were forced to close for varying periods, with others sending whole classes home.
"Wearing masks for kids in schools isn't convenient, it isn't natural," Mr Malinauskas told reporters on Tuesday.
"But we're making this decision in their best interests. In the best interests of trying to minimise the disruption to the learning environment.
"Our task here is trying to get the balance right. Allowing schools to return to normal but at the same time minimising disruption and allowing them to operate and remain open."
The premier said the state government would accelerate work to check on and improve the ventilation status in hundreds of schools and was buying another 1000 air purifiers at a cost of about $535,000.
He said this work was not done properly by the former Liberal government before the opening of the state's borders last year.
SA also released new modelling on Tuesday which indicated the state could expect to have more than 2000 new infections on a daily basis for some time.
It put the ongoing daily hospitalisation rate at between 180 and 200.
That came as SA reported another 3463 new infections along with seven more deaths.
Health Minister Chris Picton said despite the modelling and the decision on masks in schools, SA remained on track to drop the requirement for COVID-19 close contacts to isolate for seven days.
The change comes into effect from Saturday, bringing SA into line with NSW, Victoria, Queensland and the ACT.
It will come with new rules including a requirement for close contacts of positive cases to take five rapid antigen tests over the seven-day period.
They will also be required to wear masks when outside the home, are banned from visiting high-risk settings such as aged care centres, and must tell their employers and any schools they have contact with of their status.
Close contacts will further be urged to avoid any non-essential gatherings or contact with vulnerable people.
If they develop symptoms they must take a PCR test and isolate until receiving the result.