Cities across China have been placed on lockdown in a bid to stop the spread of a deadly new coronavirus.
Wuhan, with a population of 11 million in the province of Hubei, had its train station and airport closed, while ferries and long-distance buses have also been stopped. Experts believe the disease originated at an animal food market in the city.
Ezhou and Huanggang, also in the province of Hubei, have also been placed under strict travel restrictions. The cities, with a population of one million and seven million respectively, follow on from the travel ban implemented in Wuhan.
Chibi, with a population of around half a million people, will implement strict travel restrictions at midnight local time.
Zhijiang, with a population of 340,000, became the fifth city in Hubei to introduce travel restrictions, halting its bus operations and suspending classes at schools and educational facilities.
In the capital Beijing, authorities cancelled “major events" indefinitely, including traditional temple fairs that are a staple of Lunar New Year holiday celebrations.
Theatres, internet cafes and other hubs where people congregate in numbers have also closed. Residents have also been told to wear face masks in public to reduce the threat of contamination.
The World Health Organisation (WHO) will meet again on Thursday to decide whether to declare an international public health emergency over the disease.
Gauden Galea, the WHO’s representative in China, said: "To my knowledge, trying to contain a city of 11 million people is new to science.
"It has not been tried before as a public health measure. We cannot at this stage say it will or it will not work."
Authorities in Wuhan patrol outside the city's main train station
At least 17 people have died and 571 cases of the virus have been confirmed.
It is believed the coronavirus originated at an animal food market in Wuhan, and is now possibly mutating and can spread from human-to-human.
There have been confirmed cases in the United States, Japan, Hong Kong, Taiwan, Thailand and South Korea.
The disease has spread to 21 of China's 23 provinces, with only Gansu and Inner Mongolia with no reported cases.
University lecturer Michael Pattison, who has lived in Wuhan for 15 years, said the clampdown on travel has had a huge impact on people in the city.
He said: "It has disrupted people. Friends were expecting to be able to come back to Wuhan, now they're not sure.
British university lecturer living in Wuhan explains the impact of the travel ban
"Colleagues who were going to fly back to Europe have had their flights cancelled, so they're stranded and a number of other colleagues who had flights to Malaysia have had their flights cancelled, so that's had an effect, clearly."
He added: "I'm grounded effectively so I'm staying in my apartment where I might have expected to travel a bit, move around a bit, visit friends and get out and about. Effectively, I'm grounded for now."
What do the experts know about the coronavirus?
The rapid spread of the new coronavirus has made Huawei postpone its annual developer conference.
The tech firm was due to hold a meeting in Shenzen, 600 miles south of Wuhan, on February 11 and 12, but this has been pushed back until the end of March.
Employees at a Starbucks in Beijing have had their body temperature checked, as customers were advised about upgraded hygiene measures at the coffee shop chain amid the deadly coronavirus outbreak.
All employees would have their temperature taken, and would wear masks for theirs and their costumers’ protection, a statement on the counter said.
The UK Government announced all direct flights from Wuhan into Heathrow would be subject to enhanced monitoring, while the Foreign Office advised against all but essential travel to the city.
Airports in Asia and across the world have stepped up their screening to stop the spread of the disease. Dubai International Airport, the world's busiest for international travel, said it was taking special precautions.
Additional security checks have been rolled out at Rome airport
Health Secretary Matt Hancock has said there is an "increased likelihood" of cases of the new coronavirus in the UK, but insisted the risk to the public remains low and the country is "well prepared".
In a Commons statement, he told MPs: "The chief medical officer has revised the risk to the UK population from 'very low' to 'low' and has concluded that while there is an increased likelihood that cases may arise in this country, we are well prepared and well equipped to deal with them."
He added symptoms of the coronavirus do not typically appear until five to seven days, and sometimes up to 14 days after a person has been infected, making the task more difficult for experts to detect.
He said: "Having said that, we do not expect further flights from Wuhan because the Chinese authorities have taken steps to stop travel out of the city."
He added: "Currently, the current evidence suggests the vast majority of cases are in Wuhan. Obviously we keep that under constant review."
Following a meeting of an emergency committee on Wednesday, WHO director-general Tedros Adhanom Ghebreysus said: “There was an excellent discussion during the committee today, but it was also clear that, to proceed, we need more information.
"For that reason, I have decided to ask the emergency committee to meet again tomorrow to continue their discussion and the chair, Dr Houssin, has agreed with that request.
“The decision about whether or not to declare a public health emergency of international concern is one I take extremely seriously, and one I am only prepared to make with appropriate consideration of all the evidence.”
He said there is a team in China working with local experts and officials to investigate the outbreak, and he added: “We will have much more to say tomorrow.”
On Wednesday, the Department of Health and Social Care (DHSC) said precautionary measures were being put in place at Heathrow after cases of the virus spread to other parts of the world.
There are three direct flights a week from Wuhan in China to Heathrow Airport, landing at around 6pm on Monday, Wednesday and Friday.
Under the new measures, it was planned that planes would be taken to an isolated area of terminal four.
The captain of each flight would then tell passengers during landing to let a flight attendant know if they feel unwell, and these details would then be passed on to public health teams at the airport who would carry out further checks.
Meanwhile, the Foreign and Commonwealth Office updated its travel advice for China, with a spokesman saying: “In light of the latest medical information, including reports of some person-to-person transmission, and the Chinese authorities’ own advice, we are now advising against all but essential travel to Wuhan.
“The safety and security of British nationals is always our primary concern and we advise British nationals travelling to China to remain vigilant and check our travel advice on gov.uk.”
Public Health England (PHE) upgraded the risk to the UK population from coronavirus from “very low” to “low”.
A handful of cases have been identified abroad, including in Japan and the US, but there have been no reported cases in the UK.
Professor Neil Ferguson, director of the Medical Research Centre for Global Infectious Disease Analysis, said the estimated number of people infected with coronavirus in Wuhan is around 4,000, with a range between 1,000 and 9,700.
Asked whether it was possible the virus had already reached the UK, professor Ferguson said he could not rule it out.
He said: “We can’t rule out that possibility.
“Border screening, and in this case, in the UK, alerting the health system is not 100% foolproof – there could be a mild case.
“The UK is not a major destination of visitors travelling out of Wuhan around the world though.
“So I would say it was unlikely, but can’t be completely sure.”
Explaining why there is global concern about the virus, Dr Josie Golding, epidemics lead at Wellcome, said it was because so little is known about it.
She added that there was a lot of “missing information”, like how easily it can be transmitted and where it is coming from.