The number of new coronavirus infections among passengers and crew of the Diamond Princess cruise ship quarantined near Tokyo has risen by 70 to 355, the government said Sunday, while more domestic cases were also reported and experts warned the situation could worsen.

Of the 70, 38 did not show symptoms such as fever and coughing, the Ministry of Health, Labor and Welfare said. It has so far tested a total of 1,219 people aboard the ship, which currently houses about 3,400 passengers and crew.

The development came as two U.S. government-chartered planes were set to arrive in Japan to evacuate the approximately 400 U.S. citizens aboard the ship.

Canada, Hong Kong and Israel have also said they are preparing to send chartered flights to Japan to evacuate their citizens from the vessel.

Japan in the evening sent its fifth chartered flight to evacuate nationals from the central Chinese city of Wuhan, the epicenter of the outbreak. More than 700 people were repatriated on the four previous flights.