Royal Caribbean announced Friday that all passengers with passports issued by China, Hong Kong and Macau will not be allowed to board their cruise ships -- regardless of when the passengers were last in Asia.

The ban comes after four members of a family who had traveled to China before boarding a Royal Caribbean cruise ship that docked in Bayonne, New Jersey were screened for novel coronavirus on Friday. The Centers for Disease Control said the passengers were screened out of "an abundance of caution."

One of the passengers "tested positive onboard for Influenza A" and none of the four tested passengers have actually shown any signs or symptoms of coronavirus, Royal Caribbean said in a statement. The family were last in China on January 26th and not in the Hubei Province where the novel coronavirus epidemic started. They were aboard the Anthem of the Seas ship which left Cape Liberty in Bayonne on January 27th and visited several ports in the Caribbean before returning back to port in Bayonne on Friday morning.

The four passengers who had recently been in China were taken to a local hospital while they await their test results, according to Bayonne mayor Jimmy Davis. Approximately two dozen other cruise passengers were also screened for coronavirus and released, Davis said.

Royal Caribbean had first updated its policy Thursday to say "the company would now bar any passenger or crewmember -- of any nationality -- from embarking their ships if the person had traveled in the past 15 days to mainland China, Hong Kong, or Macau."

By Friday afternoon, that ban was extended to anyone holding a passport from those countries regardless of last travel. "We know that these steps are very conservative, and we apologize that they will inconvenience some of our guests. We regret to have to do this, but it is our responsibility to maintain a safe and healthy environment onboard our ships, as well as in the ports we visit," the company said on its website. The ban is for the entire month of February.

The company is also performing mandatory "specialized" screenings on passengers who "are unsure if they have been in contact with individuals who have traveled from, to or through mainland China or Hong Kong in the past 15 days." An inquiry to Royal Caribbean as to how this policy will be executed was not immediately answered.

"Guests who report feeling unwell or demonstrate any flu-like symptoms" also face additional screening, and "any guest presenting with fever or low blood oximetry in the specialized health screening will be denied boarding," Royal Caribbean said on its website.

There have been no confirmed cases of coronavirus in the tri-state area, though five New Yorkers have had their samples sent for testing at the Centers for Disease Control and Prevention. Four of these cases have tested negative and the fifth case is pending.

The federal Department of Health and Human Services announced February 2nd that the U.S. will temporarily ban the entry of any foreign nationals who have traveled to China within the last 14 days, other than immediate family of U.S. citizens and permanent residents. All U.S. citizens who have traveled to the Hubei province in the past two weeks face a mandatory quarantine of up to 14 days.

Many airlines have cancelled flights in and out of China during the outbreak. But this seems to be the first move by a private American company to ban customers solely on basis of citizenship instead of past travel to affected areas.