U.S. authorities on Sunday were monitoring dozens of cruise ships hit by COVID-19 cases while sailing in the country's waters, with several of them reportedly denied port in the Caribbean.
Over 60 vessels were under observation after "reported cases of COVID-19 have met the threshold for CDC investigation," the U.S. Centers for Disease Control and Prevention said.
The Washington Post reported that several cruise liners were denied port at their scheduled destinations.
One of them, the Carnival Freedom, was turned away from the Caribbean island of Bonaire, the Post reported.
"We're sailing on a petri dish," said Ashley Peterson, a 34-year-old passenger on board, cited by the Post. "I feel like I just spent my past week at a superspreader event."
In a statement to AFP, Carnival confirmed that "a small number on board were isolated due to a positive COVID test."
"The rapid spread of the omicron variant may shape how some destination authorities with limited medical resources may view even a small number of cases, even when they are being managed with our vigorous protocols," the company said, without providing further details.
The Carnival Freedom arrived in Miami Sunday morning, debarked all guests and "will depart on its next voyage as planned," the company said, adding if it was denied entry to a certain port it would work "to find an alternative destination."
It added the CDC was "fully informed and supportive of our protocols and operational plans."
Earlier this week, 55 people tested positive for COVID-19 aboard a Royal Caribbean International cruise, the company said.
The infections spread among passengers and crew members on the "Odyssey of the Seas" despite 95% of the people on board being vaccinated against the coronavirus, according to Royal Caribbean.
The ship did not dock at the Caribbean islands of Curacao and Aruba, the last scheduled stops on its eight-day voyage out of precaution.
It returned to port at Fort Lauderdale, Florida, on Sunday.