BEIJING: China is putting on lockdown a city of 11 million people considered the epicenter of a new coronavirus outbreak that has killed 17 and infected nearly 600, as health authorities around the world scramble to prevent a global pandemic.

Health officials fear the transmission rate will accelerate as hundreds of millions of Chinese travel at home and abroad during week-long holidays for Lunar New Year, which begins on Saturday.

The previously unknown virus strain is believed to have emerged late last year from illegally traded wildlife at an animal market in China’s central city of Wuhan.

Cases have been detected as far away as the United States, stoking fears the virus is already spreading worldwide.

Wuhan’s local government said it would shut down all urban transport networks and suspend outgoing flights from 10 a.m. (0200 GMT) on Thursday, state media said. Domestic media said some airlines were operating after the deadline, however.

State media broadcast images of one of Wuhan’s key transport hubs, the Hankou rail station, nearly deserted, with gates blocked or barred. The government is urging citizens not to leave the city, except in special circumstances.

Guards were patrolling major highways, one resident, although the shutdown notice had not mentioned private cars leaving the city, while videos on social media showed long queues at gas stations.

In contrast with its secrecy over the 2002-03 Severe Acute Respiratory Syndrome (SARS) that killed nearly 800 people, China’s communist government has this time provided regular updates to avoid panic ahead of the holidays.

Authorities had confirmed 571 cases and 17 deaths by the end of Wednesday, China’s National Health Commission said. Earlier, it said another 393 suspected cases had been reported.

Of eight known cases worldwide, Thailand has confirmed four, while Japan, South Korea, Taiwan and the United States have reported one each.

At least 16 people who had close contact with a Washington state man diagnosed with the virus are being monitored.

VIRUS SPREADING In a report on Wednesday, Imperial College London said it estimated a total of 4,000 cases of the coronavirus in Wuhan alone as of Jan. 18, an infection rate based on the number of cases reported in China and elsewhere.

During a visit to Wuhan, Vice Premier Sun Chunlan said authorities needed to be open about the spread of the virus and efforts to contain it, the official Xinhua news agency said on Thursday, comments likely to reassure global health experts.

The World Health Organization (WHO) has said it will decide on Thursday whether to declare the outbreak a global health emergency, which would step up the international response.

If it does so, it will be the sixth international public health emergency to be declared in the last decade.

Some experts believe the new virus is not as dangerous as previous coronaviruses such as SARS and Middle East Respiratory Syndrome (MERS), which has killed more than 700 people since 2012.

“The early evidence at this stage would suggest it’s not as severe a disease as SARS or MERS,” Australia’s Chief Medical Officer Brendan Murphy told reporters on Thursday.

WHO Director-General Tedros Adhanom Ghebreyesus told reporters in Geneva that China’s actions so far were “very strong” but called on Beijing to take “more and significant measures to limit or minimize the international spread”.

He added, “We stressed to them that by having a strong action not only they will control the outbreak in their country but they will also minimize the chances of this outbreak spreading internationally. So they recognize that.”

Despite China’s response, stock markets across Asia were on the back foot on Thursday over the virus, led by drops of roughly 1.5% in Hong Kong and Shanghai while China’s yuan fell to a two-week low.

FLIGHTS, RAIL SUSPENDED

Wuhan is a transport hub as well as central China’s main industrial and commercial center. The virus also has been reported in other major cities including Beijing, Shanghai and Hong Kong.

There is no known cure for the virus. Symptoms include fever, difficulty in breathing and cough, similar to many other respiratory illnesses, and can cause pneumonia.

Chinese authorities are still investigating its origins, though they confirmed the outbreak began at a market in Wuhan with illegal wildlife transactions, and the virus can spread among people through respiratory transmission. Confirmed sufferers include 15 medical workers.

Many Chinese were cancelling trips, buying face masks, avoiding public places such as cinemas and shopping centers, and even turning to an online plague simulation game as a way to cope.

Taiwan’s China Airlines said it had suspended flights to Wuhan and Hong Kong’s MTR Corp said it had suspended sales of high-speed rail tickets to and from Wuhan.

A growing number of Chinese-listed companies, from biotech firms, drugmakers, mask producers to thermometer makers, say they are actively participating in a government-led war on the coronavirus.

Wuhan Guide Infrared Co told the official China Securities Journal it had donated 4 million yuan ($579,370) worth of infrared thermometer devices to the government of Hubei, the province at the center of the outbreak.

Airports globally stepped up screening of passengers from China and the European Centre for Disease Control and Prevention (ECDC) said in a risk assessment that further global spread of the virus was likely.

Australia and Britain are among the countries that have advised citizens against all but essential travel to Wuhan.