Hundreds of Royal Caribbean passengers fall ill on Oasis ship

Almost 500 passengers and crew became sick on a Royal Caribbean cruise, cutting short a seven-night cruise to the Caribbean.

The New York-listed cruise major said Thursday that 277 people had "experienced gastrointestinal illness, thought to be norovirus," CNN has reported.

That number jumped to 475 passengers and crew Saturday, prompting the 5,400-berth Oasis of the Seas (built 2009) to return to Port Canaveral, Florida, a day earlier than expected.