MONTEVIDEO, URUGUAY - Nearly 60 percent of 217 people - many from Australia, Europe and the United States - tested on board a cruise ship off the coast of Uruguay are positive for the new coronavirus, the ship's operator said Tuesday.

"There are currently no fevers on board and all are asymptomatic," said Aurora Expeditions, the Australian operator of the ship, which is working to disembark the crew and passengers and arrange flights to their home countries.

The Greg Mortimer departed March 15 on a voyage to Antarctica and South Georgia that was titled "In Shackleton's Footsteps," a reference to the polar explorer who led British expeditions to the region and died there in 1922.

Of 217 people tested on the vessel, 128 were positive for the virus that causes the COVID-19 disease and 89 tested negative, Aurora Expeditions said. Another six people from the ship are onshore in "stable" condition, the company said.

Australian passengers, and possibly those from New Zealand, are likely to fly home on Thursday or Friday on an Airbus 340 that has been refitted, with people who have the virus and those who do not traveling in separate cabin areas, according to Aurora Expeditions. The cost per passenger is about $9,300 and the cruise ship operator has asked the Australian government for help with expenses.

The plan would require the passengers to undergo a 14-day quarantine on arrival at a facility in Melbourne, the company said.

U.S. and European passengers who tested negative may be able to depart later in the week, following a second test and permission from the Uruguayan government, Aurora Expeditions said. Those who tested positive must wait until they test negative before flying home.