Ten more people on a quarantined cruise liner in a Japanese port have tested positive for coronavirus, officials said on Thursday, as the virus death toll in mainland China hit 563, with almost 3,000 new cases reported.

About 3,700 people on Carnival's Diamond Princess are facing at least two weeks quarantine on the ship, which has 20 virus cases and testing is continuing. Japan now has 40 virus cases.

"We are hopeful that the US government will be sending transport for the Americans on board," Gay Courter, a 75-year-old American novelist aboard the ship, told Reuters.

"It's better for us to travel while healthy and also if we get sick to be treated in American hospitals."

In Hong Kong a cruise ship with 3,600 passengers and crew was quarantined for a second day on Thursday pending testing after three positive cases onboard.

Authorities said 33 crew members on the World Dream had developed respiratory tract infection symptoms and three had been sent to a hospital for isolation and management after developing fevers.

All but one of the 33 tested negative for the disease, with the remaining test pending, the city's health department said in a statement late on Wednesday.

Taiwan's health authority banned all international cruise ships from docking at the island from Thursday.

Another hotspot emerged with at least three people contracting the disease after attending a mid-January company meeting held with 94 overseas staff, including one from Wuhan, at the Grand Hyatt hotel in Singapore.

Authorities have not revealed the name of the company, but the World Health Organisation said it was investigating.

The case provided more evidence the virus is spreading through human-to-human contact outside China, which the WHO has said is deeply concerning and could signal a much larger outbreak.

The virus death toll in mainland China jumped by 73 to 563 on Thursday, its third consecutive record daily rise, as experts intensified efforts to find a vaccine for a disease that has shut down Chinese cities and factories and could damage the world's second-largest economy.

Hubei province, the epicentre of the epidemic, reported 70 new deaths on Wednesday and 2,987 new confirmed cases — more than 80 per cent of the total reported by Chinese authorities. The other fatalities were in Tianjin city, the northeastern province of Heilongjiang and Guizhou province in the southwest.

Hubei province in central China has been in virtual lockdown for nearly two weeks, with its train stations and airports shut and its roads sealed off. The flu-like virus was first identified in Hubei's capital Wuhan and is believed to have originated at a seafood market in the city.

There have been two deaths outside mainland China — in the Philippines and Hong Kong — both involving people who had been to Wuhan where more than 400 people have died.

Nearly 260 cases have been reported in 31 other countries and regions outside mainland China, according to a Reuters tally based on official statements from the authorities involved.

Evacuations continue

Hundreds of foreigners have been evacuated from Wuhan and placed in quarantine centres around the world.

In the United States, another 350 American evacuees from Wuhan were placed under quarantine at two military bases in California, bringing to nearly 400 the number of people subject to the US Centers for Disease Control and Prevention's (CDC) first public health quarantine in 50 years.

"We are in a critical time period in the international spread of the virus, and this action is necessary to try to prevent the spread here," said Dr Christopher Braden, deputy director of the CDC's National Center for Emerging and Zoonotic Infectious Diseases.

More than two dozen airlines have suspended or restricted flights to China and several countries, including the United States, have banned entry to anyone who has been in China over the previous two weeks.

Hong Kong said all visitors from mainland China would be quarantined for two weeks, while Taiwan extended a ban on entry to foreigners who had been to mainland China in the past 14 days to include those from Hong Kong and Macau as well.

Search for treatment

Hundreds of experts will gather in Geneva next week, on Feb 11-12, in an attempt to find a way to fight back against the outbreak by speeding research into drugs and vaccines, the World Health Organisation (WHO) said.

A multinational WHO-led team would go to China "very soon", it added.

Asked about reports of "drug breakthroughs" which boosted sentiment on financial markets, WHO spokesman Tarik Jasarevic said: "There are no known effective therapeutics against this 2019-nCoV (virus)."

While most people infected with the virus recover quickly with only mild symptoms, it can lead to pneumonia and other severe respiratory illnesses. It is still too early to know what its death rate will be, since there are likely to be many mild cases going undetected.

China's National Health Commission said another 3,694 coronavirus cases were reported throughout the country on Feb 5, bringing the total to 28,018. It was the first day in over a week since testing rates stabilised that new daily cases in China had gone down.

China has bristled at some international measures to shut off borders to Chinese travellers.

"The Chinese people are using all their strength to fight the epidemic and we are fully confident and capable of winning the battle of epidemic prevention and control," Chinese Vice Foreign Minister Le Yucheng said, according to a ministry statement.

Many analysts cut their growth outlook for the Chinese economy as the epidemic spread, but global markets have stabilised in recent days on central bank stimulus measures and media reports of "breakthrough" drugs.

Asian stocks edged up on Thursday after European stocks jumped sharply, US Treasury yields rose and US stock index futures surged.

Fitch Ratings said a shock to China's services sector and industrial output similar in scale to that from SARS — another coronavirus originating from China that killed almost 800 people in a pandemic in 2002-2003 — would cut its first-quarter economic growth to around 4% year-on-year, from 6pc in the last quarter.