The Northern Territory has reported 625 new COVID-19 cases with concerning outbreaks in remote Indigenous communities from Arnhem Land to central Australia.
Among the newly infected are eight people in Utopia, 240km north of Alice Springs, where the vaccination rate was about 40 per cent.
Ten have also tested positive in the nearby communities of Areyonga and Papunya, and one case was detected in Bulla, about 370km south of Darwin.
Eight more cases were also detected in Galiwin'ku, 515km east of Darwin in East Arnhem, bringing the cluster on Elcho Island to 27.
"In the last few days we have seen the number of cases presenting in more and more communities (increasing), particularly in central Australia and now in East Arnhem, that is of concern," Acting Chief Health Officer Marco Briceno said on Tuesday.
"We are working very closely with the local Aboriginal medical services, with the other government agencies and communities to ensure we are responding to those outbreaks appropriately."
Meanwhile, health workers were stumped by a case in Alyangula, on Groote Eylandt in the Gulf of Carpentaria, after it was revealed the patient does not have a "known travel history".
Thirteen new infections were also detected in an Alice Springs renal hostel and 13 at the local prison, bringing an outbreak at the correctional facility to 35.
Two new cases were found in town camps and seven at Amoonguna just outside the city, bringing the community's cluster to 28 cases.
North of Alice Springs, an outbreak grew by nine cases in Yuendumu, 295km northwest of Alice Springs, bringing the total number of infections in the cluster to 66.
No new infections were detected in nearby Yuelamu after wet season rains blocked roads and closed the airstrip.
Across the remote communities serviced by NT Health, 77 per cent of residents aged five and over have had one vaccination dose, and 69 per cent are double dosed.
But the figures do not include the 29 communities with Aboriginal-controlled health organisations where vaccination rates are much lower.
"This is a large jump on the figures we provided yesterday," Health Minister Natasha Fyles said of the 625 new cases.
"But we did in a way expect this. It's not greatly concerning to us."
Ms Fyles said the 14-day average was 400 new infections per day and Tuesday's high case tally reflected a previous lull in testing.
There are 4132 active cases in the territory with the majority in and around the two largest population centres of Darwin and Alice Springs.
Forty-three infected people are in territory hospitals - less than one per cent of the current caseload - with 27 experiencing severe symptoms and one in intensive care.
About 30 per cent of the territory's 246,500-strong population are Indigenous.
The NT detected 284 new cases on Monday, 327 on Sunday, 412 on Saturday, 546 on Friday, 550 on Thursday, 352 on Wednesday and 594 on Tuesday.
