The Northern Territory has recorded two more Delta variant COVID-19 cases as an outbreak that started in a central Australian mine grows.
The most recent cases are the wife and daughter of a worker who left Newmont's Granites Mine, about 540km northwest of Alice Springs, on Friday.
The Palmerston family tested positive while isolating at the Howard Springs quarantine facility, Chief Minister Michael Gunner told reporters Tuesday.
"We can't be certain, but we are hopeful that the two new cases became infectious while isolating", he said.
There are now nine cases linked to the mine, which started when a Victorian man, who had travelled to the mine on 18 June via a Brisbane quarantine hotel, tested positive on Saturday.
Mr Gunner said the two women attended a Zumba class in Palmerston between 9am and 9:30am on Saturday and it was now a close contact exposure site.
Everyone who attended the class and their household contacts have been ordered to isolate at home for 14 days.
About 250 fly-in, fly-out mine workers have travelled to Western Australia from the mine since 18 June.
Another 170 flew to Queensland, 29 headed to South Australia, and six to Victoria.
Three workers headed for Tasmania and two miners went to New Zealand, with 259 remaining in the Top End.
One positive case was located in NSW and another in Queensland.
Two other infected miners who had not left the Tanami Desert site were evacuated to Howard Springs.
A Darwin man in his 50s, who left the mine on Friday, was also infected.
He travelled to multiple venues, including the Buff Club for more than four hours, before being ordered into quarantine.
NT Health estimated there were about 180 close contacts from the members-only watering hole but on Tuesday had only contacted about 60.
However, seven of his close contacts, including a taxi driver, have been found and moved to the Howard Springs facility to quarantine.
Public exposure sites include the Darwin International Airport departure lounge, Bunnings Darwin, the Chungwua Terrace public toilet and the Commonwealth Bank on Smith Street in the CBD.
The lockdown encompasses the Darwin, Palmerston and Litchfield local government areas, and Wagait and Belyuen Shires, with anyone leaving their home required to wear a face mask.
Residents are only permitted to leave home for medical treatment, to obtain essential goods and services, for work considered essential, one hour of exercise a day or to provide care.
Newmont was contacted for comment on Sunday.
