Hundreds of passengers have been taken ill by a gastro bug on a Royal Caribbean cruise ship, which returned to Florida at the weekend.

Independence of the Seas docked at Port Everglades after a five-night Caribbean cruise with 332 cases of suspected norovirus.

The cruise line confirmed the outbreak and those affected were treated with over-the-counter medicine.

News station WPLG said passengers disembarking the ship believed the number of cases was much higher than had been reported.

Medical facilities were overwhelmed by the number of sick passengers and some were told they would likely have to wait up to four hours to be treated, according to WPLG.

The first signs of a fast spreading gastro bug were noticed two days into the cruise, arriving passengers told reporters.

Intensive sanitation measures were immediately taken onboard to kill the spread of bacteria, spokesman Owen Torres told CNN.

The ship also 'underwent special additional cleaning procedures before departing on its next cruise.'

"We encouraged our guests and crew to wash their hands often, which health experts recommend as the best defense against stomach viruses, which each year affect as many as 300 million people worldwide," he said.

Courtesy of Travelmole