The Northern Territory's COVID outbreak continues to spread, with three new cases detected and wastewater indicating there may be more to come.
A Katherine man in his 40s, a 20-year-old Binjari woman and an infant from Robinson River have all tested positive for the virus, with the baby boy sent to hospital for treatment.
Chief Minister Michael Gunner told reporters on Tuesday that the child is in a stable condition at Royal Darwin Hospital.
The woman, who has serious respiratory symptoms, and the man are quarantining in the Centre for National Resilience.
The latest infections bring the current outbreak to 40 cases, five of whom are in hospital, two requiring oxygen.
The Greater Katherine area, about 320km south of Darwin, remains locked down, along with Binjari and the neighbouring community of Rockhole.
It's the second time the Katherine lockdown, which started seven days ago, has been extended, with residents only permitted to leave their homes for the five essential reasons.
Mr Gunner said the town was likely to have some form of lockdown or lockout until December 4.
That may be lifted once it reaches the 80 per cent fully vaccinated rate.
The town's current first dose rate is 83 per cent, with 77 per cent of people fully vaccinated.
The outbreak started when an infected woman illegally entered the NT in late October.
The 21-year-old lied on her border entry form before travelling from Cairns to Darwin after visiting Victoria, where she contracted the virus.
She infected a man in Darwin before the virus spread to Katherine, then the Aboriginal communities of Robinson River and Binjari.
Binjari, 330km south of Darwin, and Rockhole remain under extreme lockdown orders.
The communities' 300 residents are only allowed to leave their homes in an emergency or for medical treatment.
Vaccination rates in Binjari and Rockhole were reported as being below 70 per cent when the crisis started, with the NT Aboriginal health organisation declining to make the figures public.
All virus tests from Rockhole have so far come back negative.
Restrictions have eased at Robinson River, 1000km southeast of Darwin, in recent days, with the lockdown downgraded to a lockout of unvaccinated people.
About 89 per cent of Robinson River's 350 residents have had one vaccine dose and 79 per cent are fully vaccinated.
