The health ministry let 23 passengers off the Diamond Princess cruise ship without going through mandated tests for the novel coronavirus, health minister Katsunobu Kato said Saturday.

For three days through Friday, 970 passengers who tested negative in tests after Feb. 5 were allowed to disembark the ship. The 23 passengers had been tested before Feb. 5, but results came back negative.

Having negative results was a condition to be allowed to get off the cruise liner that has seen more than 600 cases of passengers and crew members infected with the virus, NHK reported.