A Darwin couple in their 70s have tested positive for coronavirus after returning from an overseas trip, bringing the Northern Territory's number of confirmed cases up to eight.

Key points: NT authorities will enforce self-isolation protocols, if needed

NT authorities will enforce self-isolation protocols, if needed The number of COVID-19 cases in the NT now stands at eight

The number of COVID-19 cases in the NT now stands at eight There are no cases of community transmission as yet in the NT

The pair had followed self-isolation measures after returning from their travel.

They felt unwell two days into their self-isolation and went to Royal Darwin Hospital where they remain.

The NT Health Department's Chief Medical Officer Hugh Heggie said contact tracing had now begun.

"Those people who came into close contact with someone who has the virus are now in quarantine and they can be in quarantine at home or in their hotel," he said.

Dr Heggie said NT authorities expected to see more COVID-19 cases emerge in the coming days.

NT COVID-19 snapshot Cases detected in the NT: 30

Cases detected in the NT: 30 Tests conducted: 5,527

Tests conducted: 5,527 People recovered: 28 Get the latest information from the SecureNT website.

"The bigger problem is people who have a mild illness, they've walked through the community and they've shed the virus, it's a very infectious virus," he said.

"So it makes such a difference to where that virus spreads and that 1.5 metres, if you are closer than that, the rate of infection goes up massively."

'We are in a state of emergency'

Dr Heggie said that, if required, NT authorities would detain people who did not comply with self-isolation protocols.

"We are in a state of emergency and in that there are powers that we have to direct people to do things," he said.

But Dr Heggie said Territorians should be reassured that so far there was no evidence of community transmission in the NT.

"All of the cases that have been diagnosed in the NT have come from elsewhere," he said.

Prison visits to end

NT Health Minister Natasha Fyles said all social visits to prisons would cease today to protect the prison population.

"Visits by key staff such as lawyers will continue for now," she said.

"Our prisons are open; they will remain open. Coronavirus will not be a get out of jail free card. Our prisons have a pandemic plan."

Ms Fyles said the NT would not be imposing any further restrictions on the sale of alcohol, or school closures in light of the new cases.

"We have a rapidly evolving emergency. Anything is under consideration but right not there is no active planning to further restrict sales of alcohol," she said.

"In terms of education, the Chief Minister has made it clear that until the end of term one it is a parent's choice."

Territorians who suspected people of not following social-isolation protocols were also encouraged to contact police.

"If you believe someone is doing the wrong thing, reach out to police. There are heavy penalties for people who do the wrong thing," Ms Fyles said.

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Parap Market closed for two weeks

Darwin's Parap Market has also been cancelled for two weeks in light of the growing pandemic.

Kylie McCourt from the Parap Village Traders Association said traders were devastated by the decision but felt that it was the right choice to keep people safe.

"We love our community and we don't want to put our community staff and stallholders at risk in any way," she said.

"So we're following advice from government, the AMA, and the advice that really rings hard for us is stay home and say safe."

Gas project halted

The ongoing restrictions amid the coronavirus pandemic have also seen a major gas exploration project come to a halt in the NT.

Origin Energy's Beetaloo exploration project ceased today with 45 employees currently in self-isolation.

"Given the unprecedented circumstances brought about by COVID-19 we yesterday advised the NT Minister for Primary Resources and the CEO of the Northern Land Council that we are now at a point in our current work program to safely and temporarily pause activities at our Kyalla well site and reschedule further work to the second half of the year," Origin said in a statement.

The company said it would gradually evacuate the existing staff until only a skeleton crew remained.

"During this interim period we will use Northern Territory based employees and contractors to undertake civil and other works in preparation for the resumption of activities later in the year," the company said.

Not one of the 45 staff had flown in internationally, Origin said.

How do I get tested in the NT? If you can't contact or get to your GP, but you have the symptoms, you should call 1800 008 002

If you can't contact or get to your GP, but you have the symptoms, you should call 1800 008 002 This is a dedicated NT-wide coronavirus (COVID-19) number for people who need to arrange testing only

This is a dedicated NT-wide coronavirus (COVID-19) number for people who need to arrange testing only If you live in Darwin and need to arrange testing, call the Public Health Unit on 8922 8044

If you live in Darwin and need to arrange testing, call the Public Health Unit on 8922 8044 Patients who are tested should remain isolated at home until they receive their test results

Patients who are tested should remain isolated at home until they receive their test results For general advice, Territorians can call 1800 020 080 Latest information from SecureNT website