Dozens fall sickened aboard Royal Caribbean cruise ship

(Deletes extraneous word in headline)

(Reuters) - About 90 passengers and crew on a Royal Caribbean cruise in the Gulf of Mexico have fallen sick with a gastrointestinal illness causing diarrhea and vomiting, according to the U.S. Centers for Disease Control and Prevention.

"Radiance of the Seas" departed Tampa, Florida, on Saturday for a seven-day cruise around the western Caribbean, planning to visit ports in Mexico, Honduras and Belize, according to Cruisemapper.com. An outbreak of a gastrointestinal illness was reported to the CDC's vessel sanitation program on Tuesday.

The Miami-based Royal Caribbean did not immediately return a request for comment.

Some 89 people - about 4% of the cruise ship's 2,164 passengers - have reported being sick. Two members of the 910-person crew are also sick, the CDC said.

Royal Caribbean has increased cleaning on the ship, collected stool specimens for testing and isolated sick people, the CDC said. The ship is scheduled to return to Tampa on Saturday, February 8, according to Cruisemapper.com.

The CDC has said that norovirus, a highly contagious virus causing vomiting and diarrhea, is usually the cause of stomach bugs on cruise ships. It is not yet known what caused the illness on Radiance of the Seas.

(This story has been refiled to remove the extraneous word 'sick' in headline)

(Reporting by Jessica DiNapoli in New York; Editing by Angus MacSwan)