PARIS -- An infectious outbreak reported aboard the cruise ship "Ambition", docked in Bordeaux, has been confirmed as viral gastroenteritis caused by norovirus, the prefecture of Gironde in southwestern France said in a statement on Wednesday.

No severe cases have been reported at this stage, and asymptomatic people will be allowed to leave the vessel, according to the statement.

The "Ambition", operated by British company Ambassador Cruise Line, arrived in Bordeaux on Tuesday evening. About 1,700 passengers and crew members were initially prevented from disembarking after the death of a passenger aged around 90 on board. The death may be linked to a "gastroenteritis-like illness", amid the onset of digestive symptoms in around 80 people.

Epidemiological and biological analyses later conducted at Bordeaux University Hospital confirmed the viral origin of the outbreak.

According to the statement, infected people will remain isolated on board, while quarantine and hygiene measures will continue to be enforced. The cruise operator will decide whether to continue the itinerary pending further medical information.

Highly contagious norovirus is a common cause of acute gastroenteritis and is known to cause outbreaks in closed settings such as cruise ships.