The ship is being held in the port of Yokohama, Japan

A cruise ship is being held off shore in Japan after twenty people, including three Americans, tested positive for coronavirus.

Princess Cruises confirmed to PEOPLE that ten more people on their Diamond Princess cruise liner had tested positive for the illness. In addition the Americans, those affected include seven people from Japan, three from Hong Kong, two from Australia, two from Canada, one from New Zealand, one from Taiwan and one from the Philippines.

Ten other passengers who had previously tested positive were subsequently transported to local hospitals, according to CNBC.

“Local public health authorities will be disembarking those guests for transport to local hospitals immediately,” Princess Cruises said in a statement to PEOPLE of the ten new cases. “The health and safety of our guests and crew remains our top priority. We continue to work closely with the Japan Ministry of Health on all protocols and procedures while ensuring the comfort of our guests.”

The cruise ship — which has 2,666 guests and 1,045 crew members on board — is currently quarantined in the port of Yokohama, Japan.

Japan Screens Cruise Ship Diamond Princess For The Wuhan Coronavirus
Credit: Carl Court/Getty

There are currently 12 confirmed cases of coronavirus across the U.S. as of Thursday — six in California, two in Illinois, and one each in Wisconsin, Washington, Arizona and Massachusetts.

The majority of those patients had recently returned from Hubei province in China, where the city of Wuhan — believed to be the center of the outbreak — is located.

The Chinese government has since quarantined nearly 35 million residents in and around Hubei and grounded all flights, while the three major U.S. airlines — Delta, American and United — have suspended all flights to China.

Worldwide, the outbreak has killed more than than 560 people and infected over 28,000 as of Thursday, CNN reported.

Coronavirus is a blanket term for several respiratory illnesses, ranging from the common cold to more severe viruses such as Severe Acute Respiratory Syndrome (SARS). Symptoms typically include fever, cough, trouble breathing, headache and sore throat. For people who have severe cases, it can turn into pneumonia, SARS, kidney failure and death, according to the World Health Organization.

A significant number of people are recovering from this coronavirus, as well. Chinese officials said that 262 people left the hospital on Tuesday. In the U.S., the man who had the first confirmed case of coronavirus also went home.