Article Photos: US officials probe illnesses on Caribbean cruise 2/4

Passengers from a motorcycle cruises' tour group, prepare to board the Royal Caribbean International's Explorer of the Seas, docked at Charlotte Amalie Harbor in St. Thomas, U. S. Virgin Islands, Sunday, Jan. 26, 2014. Health officials have boarded the cruise liner to investigate an illness outbreak that has stricken at least 300 people with gastrointestinal symptoms including vomiting and diarrhea. Over 13 of the 34 motorcycle riders fell ill during the trip. (AP Photo/Thomas Layer)