Vail Resorts, which owns the two resorts and Perisher in NSW, says the decision to suspend ski-lift operations is "consistent with the current stay at home directions" after sharp increases in new cases in the past weeks.

"We did not make this decision lightly as we know our employees, guests and the communities where we operate have already endured so much hardship this year," said Pete Brulisauer, senior vice president and chief operating officer of Vail Resorts Australia.

"However, we are focused first and foremost on health and safety ... and doing our part to support efforts across Victoria to address the recent rise in coronavirus cases."

Mr Brulisauer said Perisher will remain open and is unaffected by the decision, operating in accordance with COVID-19 restrictions in NSW.

"We recognise this is incredibly disappointing to our guests and pass holders, including those who have made reservations at Hotham and Falls Creek this season," he said in a statement on Thursday.

Victoria recorded 165 new cases of coronavirus on Thursday, with an outbreak at a high school becoming the state's largest cluster.

Victoria's Chief Health Officer Brett Sutton confirmed just 30 of the state's new cases were linked to known outbreaks, with 135 remaining under investigation.

Health officials have announced 158 residents living in Melbourne's nine locked-down public housing towers have coronavirus, with more than 2500 results processed.

Prof Sutton said one tower in North Melbourne will remain in "hard lockdown" after 53 people there tested positive to COVID-19.

Australian Associated Press