A baby has tested positive in Katherine, 320km south of Darwin, amid fears the Omicron variant may have reached the town.

"Concerningly, we have a mother and very young baby that are unwell," Health Minister Natasha Fyles told reporters on Wednesday.

"The baby has tested positive to COVID and is seriously unwell".

The pair have been transferred to Royal Darwin Hospital.

Authorities are also determining if they are infected with Omicron or whether the cases are part of the Delta outbreak that started in Darwin in late October.

Of the 117 cases, Ms Fyles said 29 were locally acquired, up from three cases on Tuesday.

"That is a significant increase. We are in a concerning period," she said.

"It is concerning for Territorians that rise in community transmission".

More than 30 infections are known close contacts and 48 cases were recent arrivals to the territory.

Eight hospital staff have tested positive in Darwin and another nine infections remain under investigation.

The majority of the cases are in the Darwin area.

However, five people have tested positive in Katherine and six cases were found in Yulara, 18km from Uluru.

There were also two cases detected in Borroloola, 970km southeast of Darwin.

Five people are receiving care for virus symptoms in hospital and one unvaccinated person is on a ventilator in intensive care.

The NT's previous highest daily tally was on Sunday when 95 cases were recorded.

Australian Associated Press