The Australian Open is set to head behind closed doors from tomorrow (Saturday) after Victoria Premier Daniel Andrews announced a five-day, state-wide lockdown in an effort to contain a new COVID-19 outbreak.

The announcement from Andrews today came after a group of cases linked to a quarantine program at a hotel at Melbourne Airport rose to 13 on Thursday night, with five new cases reported, including two household contacts of existing cases.

Andrews said in a statement: “In the past 24 hours, five new cases have been identified. It shows just how incredibly infectious this virus is. And our public health team tell us it’s only getting faster.

“Right now, we are reaching close contacts well within the 48-hour benchmark. But the time between exposure, incubation, symptoms and testing positive is rapidly shortening.  So much so, that even secondary close contacts are potentially infectious within that 48-hour window. In short: this hyper-infectious variant is moving at hyper-speed.”

The whole of Victoria will now move to circuit-breaker action from 11:59pm tonight local time until 11:59pm on Wednesday. Residents will only be allowed to leave home for four reasons – shopping for the things they need, care and caregiving, exercise and work, if it is essential.

The 2021 Australian Open began on Monday, although only 17,922 fans were in attendance across all venues. Organisers were given the green light to admit up to 30,000 fans per day, which represents half of the usual attendance, in line with COVID-19 restrictions. The 30,000 cap was due to be reduced to 25,000 for the final five days of the tennis grand slam, when fewer matches are taking place. The tournament will run until February 21.

The 17,922 attendance figure is in stark contrast to the opening day of the 2020 Australian Open, which was attended by 64,387 fans. Despite the restrictions, the tournament was still set to be the largest-attended event in Australia since the pandemic began, before today’s announcement.

Preparations for the Australian Open were hit after 72 players were forced to quarantine last month after entering the country on flights which included passengers that tested positive for COVID-19. Players were eventually able to leave quarantine and practice ahead of the start of the tournament.

Tennis Australia said in a statement today: “Australian Open sessions today and tonight will continue as planned with COVIDSafe protocols in place. We are notifying ticketholders, 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.”

Andrews said the Australian Open could continue “because these people are at their workplace.” “It will be happening, but there’ll be no one there watching it,” he added, according to the Associated Press news agency. “I don’t have advice to cancel the event on the basis that it’s unsafe.”

Tournament director Craig Tiley said he hoped fans would be allowed back in next week for the final four days of the Open, provided the lockdown “has done its job.” He added: “The feedback we’ve had from all the players is they just want to get on and play.

“They’ve been playing in a bubble with no crowds for pretty much a year now, so the last five days (with crowds) have been a unique experience for them.”