Four new COVID-19 cases have been detected in the Northern Territory as concern also spreads to a remote community forced into lockdown.
Lajamanu, south of Darwin, will stay in lockdown until December 11 after the virus was detected in wastewater sampling.
About 40 extra health and support staff along with police and other resources are being sent to the region to ensure everyone in the community can be tested during the next 48 hours.
Chief Minister Michael Gunner said food and power supplies to the community had been secured and the first batch of 71 tests arrived in Darwin on Sunday, and would be prioritised.
No one in that community had so far shown any symptoms of the disease and wastewater tests in surrounding communities, including Amanbidji, Bulla, Daguragu, Kalkaringi and Yuendumu, had returned negative results, he said.
Lajamanu has a low vaccination rate, with only about 35 per cent of residents double-dosed.
Acting Chief Health Officer Charles Pain said the positive wastewater test was a concern.
"If we have a wastewater positive, we expect to find a case in the community. It's been highly reliable," he said.
"There can be people who are shedding in the community and may not be actively infectious.
"We hope that will be the scenario."
The positive tests reported in the NT on Sunday included three linked to the Katherine cluster, which has grown to 56 cases.
There are now 537 close contacts linked to the cluster, with all but one contacted and isolated.
So far 518 have returned negative test results.
The fourth case is in a flight crew member who arrived from London.
All are in quarantine with the Katherine cases in isolation since before they became infectious.
Mr Gunner said the new cases and the situation in Lajamanu were evidence that "COVID is going nowhere".
"It will eventually end up everywhere. Every day we stop or slow the spread of COVID is a good day but it is hard work," he said.
"There is no single measure that can totally keep COVID out of your community."
Dr Pain said officials were waiting for results from genomic sequencing in relation to a confirmed case in a traveller from South Africa to determine if they were infected with the heavily mutated Omicron variant.
He said those test results might be available on Monday.
"It is a slightly low positive result, so we might have to do some extra testing, gathering more virus from the individual," he said.
"So we don't have that confirmation yet."
Australian Associated Press
Sign up for our newsletter to stay up to date.