TOKYO - Ten additional passengers aboard a cruise ship quarantined off the coast of Japan have tested positive for coronavirus, just one day after 10 others on the vessel were confirmed to have the illness.

Around 3,700 people face at least two weeks of quarantine aboard the cruise ship – the Diamond Princess, now docked at the port of Yokohama – as health screenings continue. Those with symptoms have been moved to medical facilities for treatment.

Only a fraction of the ship’s passengers have undergone tests so far, making it unclear whether more cases will be detected, with 10 of the 71 test results received on Thursday coming back positive.

The new infections on the locked-down cruise ship bring the total number of cases in Japan to 45, among 28,000 confirmed cases worldwide, most of them in China’s Hubei province, where the outbreak originated. Nearly 600 people have died from the virus.

The first infection aboard the Diamond Princess involved an elderly man from Hong Kong who tested positive for the novel coronavirus after he disembarked from the ship in late January, stoking fears that other passengers may have been exposed to the illness, which can spread from person-to-person.

Frightening first-hand accounts – as well as photos and videos – from passengers on the quarantined ship have emerged online, with one noting they could hear “painful coughs” of others aboard the vessel in nearby rooms. “Of course I'm worried about myself, but I'm afraid for the crews who are carrying meals and cleaning rooms,”said the passenger, who has remained anonymous.

As the disease toll continues to climb, Japanese Prime Minister Shinzo Abe signaled earlier this week that the country could expand travel restrictions on foreign nationals who have visited China recently, with the PM noting “the situation is changing by the minute” and that officials were “open-minded on what measures to take.”