BORDEAUX, France (AP) — Passengers unaffected by an illness outbreak on a British cruise ship have been allowed off the ship in the French port city of Bordeaux, while authorities confirmed the cause of the outbreak is norovirus, a nasty stomach bug that spreads easily.

French authorities had initially ordered over 1,700 passengers and crew on The Ambition cruise ship to remain on board, but then decided late Wednesday to let those unaffected disembark. One passenger was spotted raising his arms in triumph while leaving the vessel.

It was not immediately clear how many left the ship, but the British operator of the ship said Thursday that passengers are able to disembark “with all scheduled shore excursions operating as planned today.” As of Thursday morning, 60 passengers and four crew members were experiencing gastrointestinal illness, according to Ambassador Cruise Line.

French authorities said there is no link to a deadly hantavirus outbreak on a Dutch vessel that has put European health authorities on alert in recent weeks.

The Ambition was midway through a 14-night cruise from Belfast and Liverpool, with scheduled stops in northern Spain and along France’s Atlantic coast. It reached Bordeaux on Tuesday evening.

The boat will remain in Bordeaux overnight before continuing its journey on a revised itinerary from Friday to avoid bad weather.

“This will allow the ship to avoid forecast unsettled weather conditions in the Bay of Biscay this evening which would be less than ideal for guests and crew recovering from gastrointestinal illness while also providing valuable additional time for crew who have worked exceptionally hard in challenging circumstances over recent days,” Ambassador Cruise Line said.

Samples analyzed at Bordeaux University Hospital confirmed an outbreak of norovirus. Local authorities said at this stage no serious cases have been reported and that sick passengers were cared for onboard by the ship’s medical team.

The U.S. Centers for Disease Control and Prevention, which tracks outbreaks on voyages that call on U.S. and foreign ports, recorded 23 gastrointestinal outbreaks on cruise ships last year. Most were caused by norovirus, including a new strain.

Ambassador Cruise Line, a British operator catering to passengers over 50, was founded in 2021.

The operator said a 92-year-old male passenger died on Sunday but did not report any symptoms consistent with gastrointestinal illness.