A Royal Caribbean cruise ship traveling back to Tampa, Florida, had 89 passengers and 2 crew members develop symptoms of gastrointestinal illness, as reported by the Centers for Disease Control and Prevention (CDC).

The ship, called the Radiance of the Seas, set out from Florida for a seven-day cruise in the western Caribbean which included stops in Mexico, Honduras, and Belize, according to information from CruiseMapper, a cruise tracking website.

The outbreak was reported to the CDC’s vessel sanitation program on Tuesday.

Those who have fallen ill have experienced diarrhea and vomiting. At this time, the CDC says the cause is unknown. 

Although Royal Caribbean did not respond immediately to a request for comment from FOX Business, they informed USA Today that they have put in place extra precautions on board to ensure the safety and well-being of all passengers and crew members.

Ill passengers and crew were isolated from others, the CDC said, and “increased cleaning and disinfection procedures” were implemented.

Cruise ships must report gastrointestinal illnesses to the CDC, the agency noted.

“Cases reported are totals for the entire voyage,” the CDC’s website states. “It does not mean all people are sick at the same time, such as when they arrive or leave a port or ship.”

While Norovirus is “often a cause of gastrointestinal illness outbreaks on cruise ships,” the CDC says determining the cause “can take time.” Stool specimens from impacted passengers were collected to aid in the investigation.