TRAVIS AIR FORCE BASE, Calif. — Two charter flights carrying cruise ship passengers from Japan landed at military bases in California and Texas overnight, starting the clock on a quarantine period to ensure passengers don’t have the new virus that’s been spreading in Asia.

A plane carrying American passengers touched down at Travis Air Force Base in Northern California just before 11:30 p.m. Sunday, local time. A second flight arrived at Lackland Air Force Base in Texas around 2-1/2 hours later, early Monday.

Japan's Defense Minister Taro Kono had tweeted earlier that Japanese troops helped transport 340 U.S. passengers on 14 buses from Yokohama port to Tokyo's Haneda airport. About 380 Americans were on the cruise ship.

The U.S. said it arranged the evacuation because people on the Diamond Princess were at a high risk of exposure to the virus. For the departing Americans, the evacuation cuts short a 14-day quarantine that began aboard the cruise ship Feb. 5.

The State Department announced later that 14 of the evacuees received confirmed they had the virus but were allowed to board the flight because they did not have symptoms. They were being isolated separately from other passengers on the flight, the U.S. State and Health and Human Services said in a joint statement.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, said Sunday that an infected person who shows minimal symptoms could still pass the virus to someone else.

After arriving in the U.S., all of the passengers must go through another 14 days of quarantine at the military facilities — meaning they will have been under quarantine for a total of nearly four weeks.

Australia, Canada, Hong Kong and Italy were planning similar flights of passengers. Other governments, including Canada and Hong Kong, also will require the passengers to undergo a second 14-day quarantine.

Japan on Monday announced another 99 infections on the Diamond Princess, raising the ship’s total number of cases to 454. Overall, Japan has 419 confirmed cases of the virus, including one death. The United States has confirmed 15 cases within the country. Separately, one U.S. citizen died in China.

Americans Cheryl and Paul Molesky, a couple from Syracuse, New York, opted to trade one coronavirus quarantine for another, leaving the cruise ship to fly back to the U.S. Cheryl Molesky said the rising number of patients on the ship factored into the decision.

"We are glad to be going home,” Cheryl Molesky earlier told NHK TV in Japan. “It’s just a little bit disappointing that we’ll have to go through quarantine again, and we will probably not be as comfortable as the Diamond Princess, possibly.”

She sent The Associated Press a video of her and her husband boarding the plane with other Americans.

“Well, we're exhausted, but we're on the plane and that's a good feeling. Pretty miserable wearing these masks though, and everybody had to go to the bathroom on the bus,” she said.

Some American passengers said they would pass up the opportunity to fly to the United States because of the additional quarantine. There also was worry about being on a long flight with other passengers who may be infected or in an incubation period.

One of the Americans, Matthew Smith, said in a tweet Sunday that he saw a passenger with no face mask talking at close quarters with another passenger. He said he and his wife scurried away.

“If there are secondary infections on board, this is why,” he said. "And you wanted me to get on a bus with her?”

He said the American health officials who visited their room was apparently surprised that the couple had decided to stay, and wished them luck.

“Thanks, but we’re fine,” Smith said he told them.