Coronavirus cases on Japan cruise ship treble to 61 - VIDEO

Another 41 people on a cruise ship quarantined off Japan have the new coronavirus, the country's health minister said Friday, confirming more on board will now be tested for the illness.

The newly diagnosed infections mean at least 61 people from the ship have contracted the virus, which has killed hundreds of people, most of them in China, and infected more than 30,000 on the mainland.

Japanese authorities have so far tested 273 people on board the Diamond Princess, which was quarantined after a former passenger, who disembarked in Hong Kong last month, was diagnosed with the virus.

"The results of the remaining 171 tests came out and 41 tested positive," Health Minister Katsunobu Kato told reporters.

"Today they will be sent to hospitals in several prefectures, and we are now preparing for that."

"In total, out of 273 specimens, 61 tested positive," he added.

The newly diagnosed include 21 Japanese, as well as Americans, Canadians, Australians, an Argentine and a Briton.

There were more than 3,700 passengers and crew on the ship when it arrived off Japan's coast on Monday evening. It docked in Yokohama on Thursday to resupply for a quarantine that could last until February 19.

Twenty people who were earlier diagnosed with the virus have already been removed from the vessel, including one who is in serious condition, a health ministry official said, without providing further details.

Testing was initially carried out on those who displayed symptoms or had come into close contact with the former passenger diagnosed with the virus.

But Kato suggested testing would now be expanded.

Authorities will "test those who are susceptible to illness, including elderly people and those with other ailments, as well as those who had close contact with the people newly diagnosed with the virus," he said.

There were no immediate details on how many people would meet those criteria or when the testing might take place.