MEXICO CITY (AP) - A Carnival cruise on which 27 people tested positive for COVID-19 just before the ship made a stop in Belize City this week was headed back to Galveston, Texas Friday after stopping in Mexico.

The positive cases were among 26 crew members and one passenger on the Carnival Vista, which is carrying over 1,400 crew and nearly 3,000 passengers, the Belize Tourism Board said in a statement. The ship arrived Wednesday in Belize City.

All 27 were vaccinated, had mild or no symptoms, and were in isolation, according to the statement. The tourism board said 99.98% of the ship's crew was vaccinated, as well as 96.5% of its passengers.

Carnival said in a statement Friday that it was managing “a small number of positive COVID cases,” but did not specify the number.

“We have managed the situation utilizing stringent health protocols which included placing those who tested positive in isolation and close contacts in quarantine,” the statement said.

The company said it had notified all passengers on the current trip and the prior one. It said Belize health officials had randomly tested 68 Vista passengers as they disembarked and all were negative.

The ship docked in Mexico's Caribbean port of Cozumel Thursday. Passengers were scheduled to disembark in Galveston on Saturday.

Hector Sosa, spokesman for the health department in Mexico's Quintana Roo state, said Friday that they were advised well in advance of the ship's arrival of the positive cases and authorities made sure they were isolated.

Other passengers were allowed to disembark in Cozumel Thursday, he said.

“It is not the first time it has happened,” Sosa said. “We have had three cruise ships where the same thing has happened.” Nonetheless, he said their precautions have worked and not put anyone at risk.

Carnival is requiring passengers to be vaccinated, though there are exceptions for children and people with medical issues. The cruise line said in a statement Aug. 4 that passengers must wear a mask in certain indoor areas, and provide a negative COVID test within three days of embarkment for cruises beginning Aug. 14.

The Centers for Disease Control and Prevention said on its website that it had investigated the Carnival Vista and the ship remains under observation.