The Centers for Disease Control and Prevention reported Wednesday that over 100 people have fallen ill from an unknown disease on a Royal Caribbean cruise.

A gastrointestinal outbreak aboard a Royal Caribbean cruise sickened more than 140 people earlier this month, according to a report from the Center for Disease Control and Prevention’s Vessel Sanitation Program.

Gastrointestinal illness sickened more than 130 cruise ship passengers aboard a Royal Caribbean cruise earlier this month. The cause of the outbreak has not been determined.