SYDNEY — Sydney is being isolated by the rest of Australia as a COVID-19 outbreak on the city's northern beaches spreads across the metropolis, according to DPA.

Australian states began restricting anyone from Sydney and New South Wales from crossing their borders on Sunday morning local time, prompting the cancelation of the annual Dec. 26 Sydney to Hobart yacht race for the first time in 76 years.

Race organizer Noel Cornish said late on Saturday night that it was a "bitter disappointment" to cancel the race but it was impracticable to hold the famous event after Tasmania decided anyone from Sydney would have to undergo a two-week quarantine.

From Sunday morning, Western Australia banned anyone from New South Wales from entering the state.

Victoria is expected to extend its red zone beyond Sydney's northern beaches, meaning two weeks' quarantine is required to enter the state.

Queensland reimposed a border pass system on Sunday morning for people from New South Wales.

Sydney's northern beaches area began a four-day lockdown Saturday night but New South Wales Premier Gladys Berejiklian warned that restrictions could be widened across the city if there should be more infections.

The 38 cases identified in the northern beaches over the past three days have shocked the country, as COVID-19 had almost disappeared in Australia since October, thanks to strict lockdowns.

The virus strain found in Sydney is believed to have its origins in the United States but no 'patient zero' has been identified. — SPA