As many as 60 new cases of coronavirus have been recorded onboard Diamond Princess.
The ship is currently in at the Daikoku Pier Cruise Terminal in Yokohama, south of Tokyo.
The vessel was was placed in quarantine for two weeks upon arriving in Japan, after a man who disembarked in Hong kong was diagnosed with the virus.
The latest cases take the total number of infections on the ship to 130.
About 3,700 people are aboard the ship, which usually has a crew of 1,100 and a passenger capacity of 2,670.
Passengers have been allowed on decks in shifts to get fresh air and encouraged to regularly take their temperature.
Around the world, the disease has killed 908 people, chiefly in mainland China.
It has also infected more than 40,000.
Over the weekend, Jan Swartz, chief executive of Princess Cruises, released an update on the situation.