Royal Caribbean says despite its implementation of anti-COVID protocol, at least 48 people on board a ships that docked in a U.S. port over the weekend tested positive for coronavirus.

According to CNN, The Symphony of the Seas, which is the world's biggest cruise ship, returned to Miami Saturday after 48 of its over 6,000 passengers and crew tested positive for COVID during a week-long journey around the Caribbean.

Royal Caribbean issued a statement regarding the situation, saying a guest tested positive during the voyage, which prompted increased contact tracing and led to the discovery of subsequent cases.

The company said 95% of those on board were fully vaccinated, and of the people who've since tested positive, 98% were fully vaccinated. 

At this time, it is unknown whether the cases were of the Omicron variant.

The cruise line says Symphony of the Seas' future voyages weren't impacted by the incident.