The Australian Open will continue without spectators for at least the next five days, starting Saturday, after authorities ordered a snap, five-day lockdown in Melbourne on Friday to contain a new coronavirus outbreak. Under the restrictions, some five million people in Australia's second-biggest city will have to remain at home for five days from midnight, except for a limited number of permitted essential activities. Premier Daniel Andrews of Victoria state, which includes Melbourne, said the lockdown was necessary to halt an outbreak of the "hyper-infectious" UK strain of Covid-19, which leaked from a quarantine hotel at the city airport. "These restrictions are all about making sure that we respond appropriately to the fastest-moving, most infectious strain of coronavirus that we have seen," Andrews said. "I am confident that this short, sharp circuit breaker will be effective. We will be able to smother this. We will be able to prevent it getting away from us." Andrews said the Australian Open, the season's first Grand Slam tournament that began Monday, can continue without crowds. Melbourne Park had <a href="https://www.thenationalnews.com/sport/tennis/australian-open-to-be-allowed-30-000-fans-a-day-1.1156207">welcomed spectators at a limited capacity</a> for the first five days of the tournament. He said the tennis venue would be considered a "workplace" able to function with strictly limited staff. Australian Open organisers responded to the new lockdown measures by confirming that fans will not be allowed to attend the next five days and refunds would be issued to ticket holders. "Tennis Australia continues to work with the government to ensure the health and safety of everyone," a statement read on Friday. "The Victorian government has announced a five-day lockdown commencing at 11:59pm on Friday. Australian Open sessions today and tonight will continue as planned with COVIDSafe protocols in place. "We are notifying ticket holders, players and staff that there will be no fans onsite at the AO for five days, commencing from Saturday 13 February. "Full refunds will be available for anyone who has tickets for these sessions and they will be advised on how to apply as soon as possible. "The AO broadcast-only contingency plan will commence from Saturday 13 February until restrictions are lifted. Play will continue uninterrupted on the broadcast, albeit without spectators onsite. "We will provide further updates on the new conditions as soon as possible." The outbreak leaked from an airport hotel that was housing international travellers in mandatory quarantine and has so far infected 13 people, including staff and their families. Overnight it emerged that one infected person had spent several hours at a cafe in an airport terminal, potentially infecting individuals heading to other parts of Australia. Andrews acknowledged that the spread of the outbreak had so far been limited to hotel staff and their families. But he said the UK strain was "so hyper-infectious, and moves so fast, that it is presenting a very, very real challenge to our status, our stay-safe, stay-open, our precious thing that we've built." Melbourne spent more than 100 days under lockdown last year to crush an earlier coronavirus outbreak that infected thousands and killed some 800 people. That lockdown ended in late October. Two other Australian state capitals, Brisbane in the east and Perth in the west, recently underwent similar snap lockdowns in response to cases of the UK strain leaking from hotel quarantine. In both instances, the outbreak was quickly contained. Australia has been among the world's most successful countries in containing the coronavirus, with some 900 deaths for a population of 25 million.