TOKYO (AFP) - Japan has quarantined a cruise ship carrying 3,711 people and was testing passengers on Tuesday (Feb 4) for the coronavirus that originated in the central Chinese city of Wuhan after a former passenger was diagnosed with the illness in Hong Kong.

Eight people on the vessel, which arrived at Yokohama Bay on Monday, have symptoms such as fever, top government spokesman Yoshihide Suga said.

Television footage showed images of several quarantine officers entering the Diamond Princess cruise ship at the port of Yokohama on Monday evening to check the health of all 2,666 passengers and 1,045 crew members.

The move comes after an 80-year-old passenger who disembarked on Jan 25 in Hong Kong tested positive for the deadly virus.

The man "did not visit a medical centre inside the ship while he was sailing with us," cruise operator Carnival Japan said in a statement.

"According to the hospital where he is staying, his condition is stable and infection was not found among his family members who sailed with him," the statement said.

A woman in her twenties who was sailing with her mother on the ship told private broadcaster TBS on Tuesday that all passengers "were asked to stay in their rooms to wait for virus tests".

The vessel’s departure from Yokohama would be delayed by at least 24 hours to Wednesday or later, Carnival Japan said.

'QUARANTINE STATION'

The cruise ship had already been through a quarantine procedure on Saturday at a port in Naha in Japan’s southernmost prefecture of Okinawa, and quarantine officials had issued certificates allowing passengers and crew to land, Mr Suga said.

A health ministry official said no one on board at that time showed any symptoms and the case of the man who disembarked in Hong Kong was not known at that time.

But after his case emerged, a second quarantine was organised.

"Quarantine officials at Naha told us to cancel the (certificate for landing) and carry out a second quarantine as we can’t rule out the possibility of infection" after the passenger who got off in Hong Kong tested positive, he said.

Health Minister Katsunobu Kato told parliament that tests for the virus would be administered to three groups: those with symptoms, those who got off in Hong Kong, and those who had close contact with the infected passenger.

Until the results are in "everyone on board... will stay there". he said.

The decision on whether to allow the vessel to dock at Yokohama port and let passengers land on Japanese soil "will be made at the quarantine station," taking into consideration the WHO’s estimate of a 10-day incubation period, Mr Suga said.

Since Saturday, Japan has been barring foreign nationals who have been to Hubei in recent weeks, as well as holders of Chinese passports issued in Hubei. Arrivals displaying symptoms of the new virus can also be denied entry.

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A total of 11 foreigners have been barred from entering so far, the immigration agency said on Tueday.

The health ministry said as of Monday that 20 people in Japan have tested positive for the new virus, of whom four showed no symptoms.

Japan has flown more than 500 citizens out of Wuhan, the epicentre of the coronavirus.

Local carriers have suspended flights to the centre of the outbreak, with All Nippon Airways saying Tuesday its suspension would now be extended through March 28. It also announced it would reduce the number of flights to Beijing from Tokyo’s Haneda and Narita airports.