The entire state of Victoria will undergo a hard five-day lockdown to prevent a cluster of 13 Covid-19 cases from spreading further, Premier Daniel Andrews said.
The cluster is tied to a worker at a quarantine hotel in the capital Melbourne, the state's Health Department said. All 13 cases are the UK variant.
Andrews said the variant "is moving at a velocity that has not been seen anywhere in our country over the course of these last 12 months."
Spectators at sporting events will not be permitted during the lockdown, Andrews said, meaning the Australian Open -- which began Monday -- will continue play without fans.
Tennis Australia, which organizes the Open, said it would continue to "work with the government to ensure the health and safety of everyone" and offer fans refunds for their tickets.