The news came a day after hundreds of passengers left the cruise ship, which has been docked off Yokohama. More are to be released today as the two-week quarantine of the vessel draws to an end.

But onboard, the coronavirus outbreak is still raging, with the number of confirmed cases now up to 621. Japanese officials have been defending their decision to allow other passengers to depart.

Some 740 passengers of another cruise ship, in Cambodia, have been cleared to leave the country after testing negative for the virus.

Overview: The spread of cases in China appears to be slowing, but public health officials have warned against excessive optimism. Iran reported its first two deaths, while Hong Kong reported its second. And China again changed its criteria for confirming coronavirus cases, frustrating some epidemiologists.