BEIJING — Japan on Friday reported 41 new cases of a virus on a cruise ship that’s been quarantined in Yokohama harbor while the death toll in mainland China rose to 636, including a doctor who got in trouble with authorities in the communist country for sounding an early warning about the disease threat.

Two docked cruise ships with thousands of passengers and crew members remained under 14-day quarantines in Hong Kong and Japan.

The number of people infected globally has risen to more than 31,000.