CIVITAVECCHIA, Italy — Over 6,000 tourists were blocked on a cruise ship in Italy on Thursday after the vast liner was placed on lockdown over two suspected cases of the deadly coronavirus.

Samples from a Chinese couple were sent for testing after three doctors and a nurse boarded the Costa Crociere ship in the port of Civitavecchia to tend to a woman running a fever, the local health authorities said.

Costa Crociere confirmed the ship, carrying some 7,000 people including the crew, was in lockdown.

It said it a 54-year old woman from Macau "was placed in solitary confinement in the on-board hospital last night with her travel companion", and was following instructions from the Health Ministry.

The Costa Smeralda, the company's flagship and the fifth-largest cruise ship in the world, "came from Palma de Mallorca and is currently engaged in one-week cruises in the western Mediterranean," it said.

The couple flew in to Milan from Hong Kong on Jan. 25, before getting on the cruise, according to Italian media reports.

"The couple's cabin has been isolated and they are in with the doctors," an unnamed passenger was quoted as telling ANSA news agency.

"We're a bit worried of course. No-one is getting on or off the ship apart from the doctors. This holiday risks ending in a nightmare".

China reported its biggest single-day jump in novel coronavirus deaths on Thursday, as global fears deepened with at least 15 countries confirming infections.

The World Health Organization, which initially downplayed a disease that has now killed 170 in China, was preparing to meet Thursday to decide whether to declare it a global emergency. — AFP