File photo: VCG

Ten more passengers on a cruise ship quarantined in Japan were confirmed to be infected with the novel coronavirus on Thursday, bringing the total number to 20, including three from Hong Kong and one from Taiwan, according to the Japanese authority. 

A total of 3,711 passengers and staff on the cruise Diamond Princess were quarantined off the coast of Yokohama, Japan  for 14 days after 10 passengers had been confirmed to be infected with the novel coronavirus on Wednesday.

Among the passengers, 22 are Chinese, the Japanese Ministry of Health and Welfare told the Global Times on Thursday. 

Besides four Chinese, seven Japanese, three Americans, two Canadians, two Australians, one Filipino and one New Zealander have been infected, the ministry said.  

The confirmed patients have been sent to a designated institute in Kanagawa Prefecture, the ministry said. 

Japanese authorities have carried out strict checks on people on board and will ensure transparency of information to the public, an official from the Japanese Embassy in China told the Global Times on Thursday. 

The official noted that none of the confirmed patients is in serious condition. 

Tokyo Broadcasting System estimated that the final number of infected patients may exceed 100. 

The Japanese ministry said that it is possible that the number of infected patients will increase. 

In response to some media reports of medicine shortage on the ship, the ministry said they are actively working with related authorities to provide food and medicine. 

Oishi Kazunori, director of the health institute of Toyama Prefecture, told the Global Times that people on board are required to stay in their cabins. 

"The 3,700 people are sacrificing to prevent the coronavirus spreading to Japan," he said.

Oishi called for attention to the mental health of people on board as anxiety and panic may occur during the 14-day quarantine period in a confined space.  

The cruise company, California-based Princess Cruise, canceled another two trips scheduled from Yokohama on February 4 and 12, according to the company's website.  

The cruise ship docked at Yokohama, and carried out medical tests on 273 people on board on Tuesday, as they showed suspect symptoms or had close contact with a previous passenger from Hong Kong who was confirmed to be infected. 

The 80-year-old Hong Kong man boarded the ship on January 20 in Yokohama and disembarked in Hong Kong on January 25. His infection was confirmed on February 1, media reported. 

Between January 25 and February 3, the ship had visited Vietnam, Taiwan Island and Okinawa.

Several cruise lines have announced precautionary measures amid the outbreak of the novel coronavirus which originated in Wuhan, Central China's Hubei Province. 

Major cruise groups, including Princess Cruises and Carnival Cruises, have enacted controls barring guests from ships if they have traveled from or through Chinese mainland in the 14 fortnight prior to the departure date of the cruise. Royal Caribbean took a similar action, but extended the date to 15 days and also included Hong Konga, CNN reported Wednesday.