A group of Americans have cut short a 14-day quarantine on the Diamond Princess cruise ship in the port of Yokohama, near Tokyo, to be flown back to the US.

But those who have flown home from Japan will have to spend another quarantine period at US military facilities to make sure they do not have the coronavirus.

Defence minister Taro Kono tweeted that Japanese troops helped transport 340 US passengers on 14 buses from Yokohama to Haneda airport. About 380 Americans were on the cruise ship.

Among those who decided to trade one quarantine for another were Cheryl and Paul Molesky.

Paul and Cheryl Molesky
Paul and Cheryl Molesky on board the plane (Cheryl and Paul Molesky via AP)

Mrs Molesky sent The Associated Press a video of her and her husband boarding a 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.

The US embassy in Tokyo said Washington evacuated the Americans because the passengers and crew members on board the Diamond Princess were at a high risk of exposure to the virus.

The US State Department announced later that 14 of the evacuees received confirmation 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 Americans were flown to Travis Air Force Base in California and Lackland Air Force Base in Texas. After arriving in the US, all of the passengers must go through another 14 days of quarantine — meaning they will have been under quarantine for a total of nearly four weeks.

Buses carrying US passengers who were on board the Diamond Princess
Buses carrying US passengers who were on board the Diamond Princess (Jun Hirata/Kyodo News via AP)

“We are glad to be going home,” Mrs 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.”

Mrs Molesky also said she was worried about the rising number of patients on the ship.

“It’s a little bit scary with the numbers going up of the people being taken off the ship for the (virus), so I think it is time to go. I think it is time to cut our losses and take off,” she said.

On Sunday, Japan announced another 70 infections on the Diamond Princess, raising the ship’s total number of cases to 355. Overall, Japan has 413 confirmed cases of the virus, including one death.

Asked how they felt about the additional 14-day quarantine in the United States, Mr Molesky said: “If we have to go through that, we will go through that.”

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 on 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.

He said the American health officials who visited their room were apparently surprised that the couple had decided to stay. They wished the couple luck, and Smith said he told them, “thanks, but we’re fine”.