TOKYO (Reuters) - Health screening began on Tuesday for some 3,700 passengers and crew aboard a cruise liner held in quarantine at the Japanese port of Yokohama, after a Hong Kong passenger who sailed on the vessel last month tested positive for the Wuhan coronavirus.

The 80-year-old man flew to Japan and boarded the ship, the Diamond Princess, run by Carnival Japan Inc, in Yokohama on Jan. 20 and disembarked in Hong Kong on Jan. 25, the company said.

Photographs and video posted on Twitter by a passenger with the handle @daxa_tw showed masked health workers clad in blue plastic gowns walking down empty corridors as well as views of deserted lounges and a barren deck.

Guests awaiting screening were asked to stay in their cabins, where they answered a questionnaire and had their temperatures taken. But onboard announcements later in the day said about 70% of the health checks had been completed and activities were operating normally except for the casino, shops and photo studio.

Some family members expressed concern about relatives trapped on board. “Unaffected people can easily say ‘keep them out’ but my whole family wants my precious sister to come home safe,” wrote one Twitter user.

Carnival Japan, a unit of British-American cruise operator Carnival Corp, confirmed that the turnaround of the ship had been delayed by about 24 hours for authorities to review the health of all 2,666 guests and 1,045 crew on board. About half of those on board were Japanese, a company spokeswoman said.

Carnival’s Princess Cruises Japan later said cruises scheduled to depart from Yokohama on Tuesday and the western Japanese port of Kobe on Thursday would be canceled because of delays related to the coronavirus checks.

Slideshow ( 11 images )

Once everyone’s health was checked, those with fevers or who felt unwell would be tested, after which authorities would decide whether to let people leave the ship, Chief Cabinet Secretary Yoshihide Suga told a news conference in Tokyo.

EXPANDING TEST TARGET SCOPE

A health ministry official said not everyone would be tested with PCR (polymerase chain reaction) kits because it was too time-consuming and deemed unnecessary.

Public broadcaster NHK said authorities were checking whether the Hong Kong man who later tested positive had disembarked when the ship docked in Kagoshima, southwest Japan.

NHK also said that when the ship made a stop in Naha on Japan’s southern island of Okinawa, about 10 passengers got off after checks showed no passengers had fever or other symptoms.

Also on Tuesday, Japan expanded the scope of its screening for the virus generally after some people who had not met criteria for testing were later found to be infected.

Slideshow ( 11 images )

Opposition parties and some experts have criticized the government for responding too slowly to the risks following the outbreak of the coronavirus in the central Chinese city of Wuhan. So far, the epidemic that has claimed more than 420 lives in mainland China.

Chinese make up 30% of all tourists traveling to Japan and nearly 40% of the total amount foreign visitors spent last year, according to an industry survey.

Japan has 20 confirmed coronavirus cases, of these 17 people have been in Wuhan. And on Saturday, Japan 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.

Suga said that as of Feb. 3, eight foreigners had been barred from entering Japan.

Prime Minister Shinzo Abe told a parliamentary panel the government would be flexible about expanding areas in China from which visitors would be banned, depending on trends in China.

Some countries including the United States and Australia have denied entry to all foreign nationals traveling from China.

Separately, Taiwan’s government said on Tuesday it would ban cruise ships from calling at the island if they had visited China, Hong Kong or Macau in the 14 days before, or 28 days before if they had previously carried confirmed or suspected cases of the virus.