The Foreign Office has issued advice for people planning on travelling to China following the outbreak of coronavirus.
The flu-like disease originated in Wuhan, central China, and has now spread to other areas and countries around the world.
There have now also been nine confirmed cases in the UK, where more than 4,000 people have been tested for the virus.
Because it's a new illness, the NHS says that officials do not know exactly how the coronavirus is spread. But the virus belongs to the same virus family as MERS and SARS, which are spread in cough droplets.
Chinese authorities have put large parts of the country on lockdown and millions are thought to have been affected by the measures.
What is coronavirus?
Coronavirus comes from a family of viruses which give rise to a huge range of illnesses from the mild common cold to severe SARS.
It is thought to have originated from animals and traces of the disease were found at a market in Wuhan which sold poultry and seafood.
Although it is now clear how it is spread, similar viruses are spread through cough droplets and people in affected areas have started to wear face masks to try and limit its spread.
Initial symptoms include fever, cough, tightness of the chest, runny nose, headache and shortness of breath.
Chills and body aches are later signs of the strain.
Coronaviruses are named after the spikes that protrude from their membranes, like the sun’s corona.
Coronavirus outbreak: What are the symptoms?
Is it safe to travel to China?
The Foreign and Commonwealth Office (FCO) advises against all travel to Hubei Province due to the ongoing coronavirus outbreak, and all but essential travel to the rest of mainland China.
Foreign Secretary Dominic Raab has also announced that anyone in mainland China should leave the country.
Mr Raab said: “We now advise British nationals in China to leave the country if they can, to minimise their risk of exposure to the virus.
“Where there are still British nationals in Hubei province who wish to be evacuated, we will continue to work around the clock to facilitate this.”
The Chinese government continues to impose further restrictions on movement within China in response to the coronavirus outbreak.
Some airlines, including British Airways, have suspended flights to and from mainland China. Other commercial airlines are still operating, but it may become harder over the coming weeks for those who wish to leave China to do so.
The FCO said if you want to leave China soon, you should consider making plans before any further restrictions may be imposed.
Due to increasing travel restrictions and difficulty accessing medical assistance, the FCO is working to make an option available for British nationals to leave Hubei Province.
This may happen quickly and with short notice.
An FCO spokesman said: "If you’re a British national in Hubei Province and need assistance, contact our 24/7 number +86 (0) 10 8529 6600 or the FCO in London on (+44) (0)207 008 1500.
"If you have registered your desire to leave, you will be contacted once arrangements are confirmed."
In January, Wuhan authorities closed all transport hubs including airports, railway and bus stations while British Embassay and Consulate staff have also been withdrawn.
Some shops and amenities are closed, public events have been cancelled and Chinese authorities have advised the public to avoid crowds.
Travel restrictions are also in place in other cities in China.
What should I do if I've already booked flights?
The FCO is advising against all travel to the Hubei Province. Anyone travelling to China should remain vigilant and check the latest travel advice
The Chinese authorities are focused on tackling the impact of the virus in different ways, many of which are likely to impact British nationals in all areas of China, not just Hubei province.
These include temperature checks at transport hubs and other locations, quarantine arrangements for travel between different parts of the country, and restrictions on travel between and within cities.
Medical facilities across the country are under significant pressure. Some are not accepting patients and others have long queues.
Some businesses have closed and many tourist attractions are shut. The Ministry of Culture and Tourism has suspended all tour group companies’ activities to prevent further virus spread.
Public Health England has offered advice to travellers and you should comply with any additional screening measures put in place by the local authorities.
If you decide to cancel your trip, normal policy would apply and it would be best to consult your airline's website on their cancellation procedure.
If the Foreign Office warns against travel to the region, travellers on package holidays organised by a British firm should be able to cancel without a penalty and receive a full refund.
Airlines are not obliged to refund tickets whatever the Foreign Office advice, but in the past they have offered some flexibility.
Travel insurance could also be a way of recouping costs, according to the Association of British Insurers.
But, if you were to travel to an area against the advice of the Foreign Office it will invalidate most insurance policies.
If you’re abroad and you need emergency help from the UK government, contact the nearest British embassy, consulate or high commission.
If you need urgent help because something has happened to a friend or relative abroad, contact the Foreign and Commonwealth Office (FCO) in London on 020 7008 1500 (24 hours).