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

Television footage showed several quarantine officers boarding the Diamond Princess on Monday evening to check all 2,666 passengers and 1,045 crew.

The move comes after an 80-year-old passenger who disembarked on January 25 in Hong Kong tested positive for the virus, which has killed 425 people in China.

The man “did not visit a medical center 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 on the ship with her mother told private broadcaster TBS on Tuesday that all passengers had been asked to stay in their rooms and wait for tests.

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