The Northern Territory has detected 12 new COVID-19 infections as health authorities investigate a mystery case in Darwin.
A woman in her 60s is being interviewed in a bid to find the source of her infection.
Two of the other new infections are linked to the current community outbreak, bringing the cluster centred around Katherine, 320km south of Darwin, to 146 cases.
Both are people from the Tennant Creek area and household contacts of previous cases, NT Health said on Monday.
They were not infectious in the community and are in quarantine.
The other nine new cases include a close contact of two workers from Yulara who acquired their infections in Queensland.
They were not infectious in the community and are in quarantine at The Centre for National Resilience in Howard Springs, near Darwin.
Five cases are interstate arrivals and are all in isolation at home or at the Howard Springs facility.
Three cases are close contacts of interstate arrivals.
There are currently 15 people with COVID-19 in hospital, including one in intensive care.
The majority of admissions are for the purposes of infection control and assessment.
The Nhulunbuy community, 1000km east of Darwin, was encouraged to get tested for the virus after positive wastewater results were detected.
Meanwhile, police have found two men who failed to enter the Alice Springs Quarantine Facility when directed to do so.
Akiir Lueth, 29, and Pashaiy Ayiik, 31, crossed into the territory through the Kulgera check point near the border with South Australia.
The pair have each been fined $5,056 for failing to abide by the Chief Health Officer Hugh Heggie's health directions.