A seventh person evacuated from the Diamond Princess cruise ship to a quarantine site in Darwin has tested positive for coronavirus.

In a statement, the Department of Health confirmed the 57-year-old Queensland woman "has mild illness and will remain in isolation overnight at the evacuation centre".

The woman will then be "transported back to her home state on a specialised medical retrieval plane tomorrow".

The quarantine site near Darwin in the NT where passengers have been taken for a further 14 days. (9News)

Ambulances arrive at the quarantine site after more confirmed cases of COVID-19 emerge. (9News)

In an earlier statement, the Department of Health confirmed all of those who have tested positive will be taken to hospitals in their home states for treatment.

Among those now confirmed to have contracted the virus are another two people from Queensland, two people from Victoria, one person from South Australia and one person from Western Australia.

This brings the number of confirmed cases of coronavirus in Australia to 22.

The seven evacuees were among 170 people flown to the Darwin quarantine centre after staying on the Diamond Princess.

They were found to be suffering a sore throat and runny nose when they arrived.

Health authorities yesterday announced two of those – a Western Australian man and South Australian woman – had since tested positive for coronavirus.

Two Australians at the Darwin quarantine centre have tested positive to coronavirus. (9News)

"Both remain well and are being housed in a separate isolation unit at the village, while public health authorities from their home States organise medical evacuation for both the patients and their partners," Australia's Chief Medical Officer Professor Brendan Murphy said in a statement.

Public health authorities from their home states are organising medical transfers for the patients and their partners.

"Those people remain well and mildly ill with cold-like symptoms and they do not necessarily need to be in the hospital system," acting NT chief health officer Dianne Stephens said.

"But more than likely (they) will enter the hospital system in their home states while they manage the Covid-19 quarantine and isolation procedures."

Ms Stephens described the individuals as "one younger person and one older person" but declined to elaborate further.

She said their symptoms could slowly worsen over several days.

"Both these individuals will be taken into their hospital systems to watch to see whether or not they're going to improve or deteriorate," she told reporters.

"Then their own health systems have systems in place to manage the Covid-19 infected patients."

Four other people tested for coronavirus after returning to Australia yesterday have been cleared.

The number of coronavirus cases has spiked in South Korea this week. The rise is centred around the city of Daegu where residents have been urged to remain indoors. ( (Kim Jun-beom/Yonhap) (AP) (AP)

Prof Murphy said Australian authorities are monitoring China and other countries - including Japan and South Korea - where coronavirus cases are rising.

"The rate of rise of cases in other provinces of China is not as great as it was before. New case numbers seem to be growing less aggressively.

"We are watching all the countries in the region and obviously provinces outside of China.

"We are keeping an eye out for making sure our doctors and our health professionals are aware of the travel history of people stopping people who have come from a country whether a significant presence of this virus, and they have the right symptoms."

Meanwhile, two Japanese passengers on the Diamond Princess aged in their 80s have died, Japanese media reported yesterday.

Australian evacuees arrive at the quarantine centre near Darwin. Six have been isolated after health checks. (AAP)

The number of confirmed cases of coronavirus on the ship, which was carrying 3700 passengers and crew, has topped 620 and includes 36 Australians, all of whom are stable, which has prompted criticism of quarantine measures on board.

The Australian evacuees in Darwin had already been quarantined on the Diamond Princess in Yokohama for two weeks, effectively leaving them confined for almost a month

"Six people that were identified as having minor sniffles and sore throats have been separated completely, these people were tested today and they have gone into an isolation area of the Howard Springs facility," Acting NT chief health officer Dianne Stephens said.

Two Japanese passengers on the Diamond Princess aged in their 80s have died, Japanese media reported yesterday.

The number of confirmed cases of coronavirus on the ship, which was carrying 3700 passengers and crew, has topped 620 and includes 36 Australians, all of whom are stable, which has prompted criticism of quarantine measures on board.

"It just demonstrates the infectiousness of this particular virus and how it can spread very easily in a closed setting like a cruise ship," Australia's deputy chief medical officer Paul Kelly said.

Two Japanese passengers from the Diamond Princess cruise ship in Yokohama, Japan, have died.. (Getty)

Some 180 citizens and permanent residents had taken up the federal government's offer of a seat on the special Qantas evacuation flight.

But 10 were told they could not leave because they had tested positive to the deadly disease, known as COVID-19.

Another 15 had already chosen to stay behind in Japan to be near family members who have been hospitalised after contracting the virus.

The federal government announced yesterday that Australia's ban on travellers from China has been extended until February 29, locking out students and tourists as the number of cases and deaths from coronavirus grows.