By Alice Uribe

SYDNEY-- Australia's most populous state will move ahead with easing a range of pandemic-related restrictions, even as officials predict a surge in new coronavirus cases driven by the Omicron variant.

Starting Wednesday, residents in New South Wales will only need to wear masks on public transport and planes, with proof of vaccination no longer required for most activities. Electronic check-ins will only be required at high-risk venues, such as hospitals, aged and disability care facilities and gyms.

NSW on Wednesday reported 1,360 new coronavirus infections, the highest number of new infections since Sept. 11. Wednesday's figure also represents a 69% jump from Tuesday, when 804 new cases were reported. Health authorities said the rapid uptick in cases was being driven by Omicron.

NSW Health Minister Brad Hazzard said officials were "alert and cautious."

"We're facing the reality of the reproductive rate of this virus being more than 1.5. We try to keep the reproduction rate below one because that generally means a declining number of cases of the coronavirus," he said at a media conference Wednesday.

"What we are seeing now is a very substantial increase in the coronavirus, the current variant Omicron and Delta, and we're seeing every two to three days currently, we're seeing a big increase, in fact a doubling...of the number of people who are actually getting the virus."

Mr. Hazzard said epidemiologists from the University of NSW had told health authorities the state could see 25,000 new Covid-19 cases a day by the end of January.

"So, that takes us on my maths to about 175,000 in a week. That's one big difference from 1,360 today which already is a cause for concern," he said.

Australia, which has about 26 million people, has had almost 233,000 Covid-19 cases and a little over 2,100 deaths, according to Johns Hopkins University data. NSW has so far recorded 110 cases of Omicron.The U.S., with around 330 million people, has had over 50 million Covid-19 cases and almost 799,000 deaths.

Australia has had relatively few coronavirus cases and deaths during the pandemic, partly due to strict travel restrictions and lockdowns. Citizens were barred from leaving the country for much of the pandemic unless granted a rare exemption, and those returning had to quarantine in government-run facilities for two weeks.

Tourists are still mostly barred from Australia, although visitors from Japan and South Korea will be allowed in from Wednesday. Travelers from New Zealand and Singapore had earlier been permitted to visit.

"We're not going to let Omicron take us back," Mr. Morrison said Tuesday. "We have decided as a country to live with this virus and Australians have worked so hard to ensure that we can."

Australian officials have said there are indications that Omicron is milder than other Covid-19 variants and that vaccines provide protection against serious illness. Mr. Hazzard said it seems likely that vaccines aren't stopping transmission of the Omicron variant, with transmission "quite high."

New South Wales Premier Dominic Perrottet said Wednesday he had complete confidence in the health system as the state further lifted restrictions, urging residents to get boosters and exercise "personal responsibility."

"We've always said as we've opened up, as mobility increases, case numbers will increase. Case numbers alone are not the only important factor. What is important is our hospitalization and ICU presentations."

Write to Alice Uribe at alice.uribe@wsj.com

(END) Dow Jones Newswires

12-15-21 0014ET