More than 800 repatriated Australians will fly into Adelaide Airport on Monday and Tuesday to undertake mandatory coronavirus quarantine.

Key points: Two flights, holding more than 800 repatriated Australians, will fly into Adelaide

Two flights, holding more than 800 repatriated Australians, will fly into Adelaide The returning travellers will undertake their 14 days of quarantine under police guard in SA hotels

The returning travellers will undertake their 14 days of quarantine under police guard in SA hotels The state recorded zero new coronavirus cases on Saturday

The state recorded no new positive COVID-19 cases in the 24 hours to Saturday afternoon, continuing a dramatic flattening of the curve in the state over the last week.

The results came despite the testing criteria being widened over the last few days, with 41,000 tests now having been conducted on more than 2 per cent of the state's population.

There are seven people being treated in hospital, with two still in ICU including a 68-year-old man in a critical condition.

Four people have died in South Australia as a result of COVID-19 to date.

Of the state's positive cases, 79 per cent have now recovered.

"I think we can say we're not losing the war … We're in a very good place in South Australia," Dr Spurrier said.

"However, it's not over yet. We need to keep our foot down on COVID-19 and make sure we do everything we can as individuals to get rid of it."

SA to 'play its part' in hosting returning travellers

On Monday and Tuesday, South Australia will receive two flights of returning Australians who will go into quarantine in South Australian hotels.

The first flight from India to Adelaide — via Indonesia or Singapore — with 440 passengers on board is expected to arrive Monday.

They will be conveyed by bus from the airport to the Pullman Hotel on Hindmarsh Square in the city. All passengers will be tested for COVID-19.

The second flight will also carry around 440 passengers and authorities are yet to determine where they will stay.

Premier Steven Marshall said the flights to get stranded Australians back to South Australia was part of a coordinated effort with other states and territories across the country.

"All operational measures have been put in place to enforce the returning citizens' 14-day quarantine period and ultimately keep South Australia safe and strong," he said.

"We can't leave Australians stranded.

"These are Australian citizens who have been caught up and stranded with the COVID-19 pandemic, and for the most part, have found it difficult to get home.

"South Australia's successful plan to slow the spread of the disease puts this state in a strong position and we have meticulously planned and prepared to manage these arrivals."

Many South Australians have already been accommodated interstate during quarantine periods as part of the national effort.

Police Commissioner Grant Stevens said the government had two weeks to plan for these two flights returning to the state so extensive planning had gone into minimising any potential spread of COVID-19 from these passengers.

"It's a comprehensive plan," he said.

Face mask testing facilities will be set up in South Australia to support the production of respirator and surgical masks. ( ABC News: Michael Clements )

Face mask testing undertaken in local facilities

Face mask testing facilities will also be set up at South Australian universities to support the production of millions of respirator and surgical masks being made in the fight against COVID-19.

The testing facilities — at the University of South Australian and Flinders University — will be the first established in Australia.

Testing is usually done in the United States and can take three weeks.

Adelaide-based fast food packaging company Detmold has been tasked with producing 145 million masks for frontline health staff across the country.

South Australian Innovation Minister David Pisoni said the Government and both universities were collaborating to create an onshore facility that would "test the locally made medical equipment" when production kicks off next month.

"In these unprecedented circumstances, science, research, innovation and collaboration have never been more important," he said.

Police issue 16 COVID-19 expiations after car gathering

Meanwhile, SA Police issued 16 COVID-19-related expiation notices after a large group of more than 50 cars congregated in Penfield, north of Adelaide, last night.

Police were called to Pellew Road around 10:20pm on Friday after reports the group had assembled and a number of vehicles were allegedly conducting burnouts.

Officers responding to the call found some cars had already left, but five vehicles that had been involved in a collision were at the scene.

All of the drivers, including a 19-year old Paralowie man, 23-year-old Lightsview man, 21-year-old Golden Grove woman, 22-year-old Smithfield Plains man and a 22-year-old Willaston man, were issued COVID-19 expiation notices.

Five were also issued traffic expiation notices for failing to keep a safe distance from the vehicle in front.

Police then pulled over several other cars and issued 11 further COVID-19 expiation notices to drivers and passengers.

Under current South Australian COVID-19 directions, gatherings of more than 10 people, including at residences, indoors or outdoors, are prohibited.