Three coronavirus cases have been detected among charter flights carrying tennis players, coaches and officials to Melbourne for the Australian Open, forcing 47 players into strict hotel quarantine.

The players from the two affected flights - arriving from Los Angeles and Abu Dhabi - were in a strict 14-day quarantine, unable to leave their hotel rooms or practice, health authorities and tournament organizers said Saturday. The Australian Open starts on Feb. 8.

Health authorities said two positive COVID-19 cases emerged from a charter flight from Los Angeles. The third positive test was from a flight from Abu Dhabi in the past 24 hours, Tennis Australia said.

The coach of Canadian star Bianca Andreescu said he has tested positive after arriving from Abu Dhabi. Sylvain Bruneau said the “rest of my team is negative.” Andreescu will quarantine at her hotel, her agent, Jonathan Dasnieres de Veigy, said in a text to The Canadian Press.

Authorities earlier said that all passengers from the Los Angeles flight would go into the 14-day hotel quarantine.

“All remaining 66 passengers on the flight have been determined to be close contacts,” Victoria state's health department said in a statement about the Los Angeles flight. “Any players and support people will not be able to leave quarantine to attend training. The remaining flight crew all tested negative and were permitted to fly out without passengers directly to their home port.”

Australian Open tournament director Craig Tiley issued a statement saying the 24 players who were on that flight will not be able to leave their hotels rooms for 14 days and until they are medically cleared.

“We are communicating with everyone on this flight, and particularly the playing group whose conditions have now changed, to ensure their needs are being catered to as much as possible, and that they are fully appraised of the situation,” Tiley said.

Later Saturday, Tennis Australia said 23 players were among the 64 people on the flight from Abu Dhabi.

“All passengers from the flight are already in quarantine hotels and the positive case, who is not a player and had tested negative before the flight, has been transferred to a health hotel,” Tennis Australia said.

Kei Nishikori, the 2014 U.S. Open runner-up who tested negative for COVID-19 after having two positive tests, and two-time Australian Open champion Victoria Azarenka were reported by local media to be among a group of players who arrived on the flight from Los Angeles.

British player Heather Watson said on Twitter that she others who arrived from Abu Dhabi “are NOT allowed out (of) our rooms.” She posted the notification that she and others who were on the flight received informing them of the quarantine.

“The Chief Health Officer has reviewed the flight and has determined that everyone on board needs to isolate and will be confined to their rooms for the 14-day quarantine period,” said the notification, which Watson posted.

“We are aware of the major impact this has on your preparation for the Australian summer,” it continued, pledging “to do everything we can to mitigate this impact.”

Being unable to leave their room would mean the only workouts they'd be able to have would be on an exercise bike left in the rooms of all of the players.

Other players will be allowed to train under strict conditions and with supervision for up to five hours a day.

Several players in quarantine, including Sorana Cirstea of Romania, Belinda Bencic of Switzerland and Yulia Putintseva of Kazakhstan complained in social media posts that the rules seemed to have changed between what they saw before travelling to Australia and what was being imposed in Melbourne.

Cirstea posted on Twitte r: “If they would have told us this rule before I would not play Australia...I would have stayed home. They told us we would fly at 20% capacity, in sections and we would be a close contact ONLY if my team or cohort tests positive.”

Players and officials were supposed to have received a negative COVID-19 test before they boarded their flights.

Australia's international borders are basically closed to travellers, although there are exemptions for people returning home and in special circumstances. Each of Australia's states and territories has its own border and quarantine rules, and those can change on very short notice.

Azarenka, who won the tournament in 2012 and 2013, tweeted Friday: “Made it to Melbourne! Thank you everyone so much for making it happen. I can only imagine how many hours of work and compromise it took for us to be here! Thank you.”

She included what appeared to be a selfie next to a window with downtown city views. Azarenka has not tweeted again since.

The 15 charter flights and the early arrivals are all part of Tennis Australia's attempt to hold the tournament despite a general ban on international arrivals into the country.

Australia has done a good job of containing the coronavirus, with 909 deaths nationally. Victoria state, which has as its capital Melbourne, accounted for 810 of those during a deadly second wave three months ago which resulted in overnight curfews and lockdowns for the city.

Five-time finalist Andy Murray's status for the tournament was put in doubt after he tested positive for COVID-19 only days before his planned flight to Melbourne.

Also, Americans Madison Keys and Tennys Sandgren returned positive tests, but Sandgren was given permission to fly.

Sandgren originally tested positive in November, and Victorian state health authorities determined he was no longer contagious though still shedding viral particles.

The charter flights to Australia were restricted to 25% capacity, and arrived over a 36-hour period ending early Saturday.

Novak Djokovic, Rafael Nadal and Serena Williams are among a group of players involved in an exhibition event in Adelaide, South Australia state, on Jan. 29. Those players flew straight to Adelaide to begin their hotel quarantine period.

South Australia health officials “confirmed that there is no one who has an active COVID-19 infection in the entire tennis cohort based in Adelaide,” the Australian Open said Saturday on Twitter. “Testing will continue on a daily basis.”