At least 10 passengers on a cruise ship that Japan quarantined tested positive for the new coronavirus, public broadcaster NHK and other Japanese media reported on Wednesday, citing the health ministry.
Japan has quarantined the vessel carrying 3,711 people and was testing those onboard the Diamond Princess for the virus after a former passenger was diagnosed with the illness in Hong Kong.
Health screening began on Tuesday for the passengers and crew after the Hong Kong passenger who sailed on the vessel last month tested positive for the novel coronavirus.
The 80-year-old man flew to Japan and boarded the ship run by Carnival Japan Inc, in Yokohama on Jan 20 and disembarked in Hong Kong on Jan 25, the company said.
Japan was also preparing to expand the scope of its screening for the virus, and test criteria after initial tests failed to detect the virus in some people who were later found to be infected, Health Minister Katsunobu Kato told reporters.
Japan has 20 confirmed coronavirus cases previously, with 17 of them having been in Wuhan, the central Chinese city where the epidemic began.
Japan on Saturday began refusing entry to foreigners who have been in Hubei province, where Wuhan is located, in the past 14 days as well as people with passports issued in Hubei province.
Japanese Chief Cabinet Secretary Yoshihide Suga said he believed Japan's current restrictions on entry were appropriate, when asked at a news conference. Suga said that as of Feb 3, eight foreigners had been barred from entering Japan.