Two elderly former passengers from the coronavirus-wracked Diamond Princess died 0n Thursday, Japanese authorities said, as fears mount for those who have left the ship after testing negative for the virus.

The man and woman, both Japanese and in their 80s, were taken off the cruise ship last week and died in hospital, the first fatalities among the more than 600 passengers and crew who have tested positive for the virus.

The woman had no known pre-existing conditions, the direct cause of her death was pneumonia. But the man had a pre-existing condition of bronchial asthma and a history of angina treatment, the health ministry said .

The huge vessel moored in Yokohama near Tokyo is easily the biggest coronavirus cluster outside the Chinese epicentre, with 621 positive cases confirmed among the passengers and crew.

On Wednesday, 443 passengers disembarked after testing negative for the COVID-19 virus and not showing symptoms during a 14-day quarantine period. The removal of all passengers was expected to take at least three days.

More passengers left the ship Thursday, packing into yellow buses and leaving for stations and airports to head home.

But questions are increasingly being asked as to why former Diamond Princess passengers are able to roam freely around Japan’s famously crowded cities, even if they have tested negative.