By Ruth Eglash

WASHINGTON — More than three weeks after an outbreak of the deadly coronavirus sickened several people on a cruise ship in Japan, three Americans were discharged from a hospital in Tokyo after doctors cleared them of the disease.

As of Friday afternoon, 198 other passengers were still staying in a Tokyo hospital, where some have been treated in quarantine. The hospital is treating them as though they were confirmed cases of the viral disease, even though they haven’t been diagnosed or declared. Most of the visitors to the ship have since left the hospital.

The long wait for patients who were exposed to the virus — and have shown no symptoms of the virus — has been vexing to the cruise line that owns the ship.

“It would be helpful if they were cleared and could be released by tomorrow,” said Wendy Laws, a spokeswoman for Royal Caribbean Cruises.

The common coronavirus, which has been in the news for the past month since hundreds of people became sick in Hong Kong and Jordan, was not carried aboard the ship, the Majesty of the Seas. But the first nine passengers from the ship to be admitted to a hospital, in Kobe, are believed to have had direct contact with a male crew member who had come down with the virus, authorities have said. The man has recovered and returned to his home in central Japan.

The cruise ship returned to Japan on Friday, hours after many of the passengers whose symptoms were confirmed were released from the hospital, law enforcement officials said.

“Our passengers are safe, all the passengers and crew are safe and have been told that they are not contagious and they are allowed to return home,” said Tomoko Imai, a spokeswoman for Japan Coast Guard.

Some of the remaining visitors from the ship remain in “extremely serious” condition, said Haakon Skog of Copenhagen University Hospital, where the nine patients were treated. He said their condition was improving, but that he expected the rest of the passengers on the ship to be released soon.

The Royal Caribbean voyage was one of the largest cruise ships docked in Japan this year. More than 2,600 passengers were aboard the ship when it docked in Kobe on Feb. 1 and when it left March 2. It had a full complement of medical personnel and a full complement of onboard physicians and paramedics.

The majority of the remaining visitors to the hospital are from Western countries, although a few from Africa and South America also have been confirmed to have the coronavirus, Skog said.

Of the remaining tourists, one American remains in critical condition and others have recovered, Laws said.