The number of people killed in China by the coronavirus has risen to 80, with almost 3,000 confirmed ill.
The national new year holiday has been extended by three days to Sunday, in an attempt to contain the outbreak.
Wuhan in Hubei, the source of the outbreak, is in lockdown and several cities have imposed travel bans.
Health commission officials said on Monday the number of deaths in Hubei province had climbed from 56 to 76, with four deaths elsewhere.
The overall number of confirmed cases in China is 2,744. State media say more than 300 are critically ill.
Another 41 cases have been confirmed abroad, including in Thailand, the United States, and Australia. There have been no deaths outside China.
The coronavirus causes severe acute respiratory infection and there is no specific cure or vaccine.
Most deaths involve elderly people or those with pre-existing respiratory problems.
- Wuhan: The London-sized city where the virus began
- How do you quarantine a city – and does it work?
What is happening in Wuhan?
Travel from the city, home to 11 million people, has been severely restricted and non-essential vehicles have been banned from the roads.
At the Hubei border, workers are checking people’s temperatures before allowing them into the province.
The emergency has overwhelmed Wuhan’s hospitals. More than half a million medical staff have joined prevention, control and treatment operations in Hubei province.
Two new makeshift hospitals are being built in Wuhan, the provincial capital, and factories are rushing to produce masks and protective clothing.
The city’s mayor Zhou Xianwang said the number of cases would continue to rise, and warned that around five million new year travellers left the city before the lockdown.
What is the situation in China?
New year celebrations were scaled back and four major cities – Beijing, Shanghai, Xi’an and Tianjin – have banned long-distance busses.
Beijing has closed the Forbidden City for tourists, as well as a section of the Great Wall.
In Guangdong province, several cities have made face masks mandatory in public. Both Disney parks in Hong Kong and Shanghai have closed.
On the weekend, Chinese officials warned the virus was able to spread during its incubation period, making it harder to contain the illness.
In humans, the incubation period – during which a person has the disease, but no symptoms – ranges from between one and 14 days, officials believe.
- Coronavirus: How worried should we be?
- Has China learned lessons since deadly Sars epidemic?
What is the situation internationally?
According to the World Health Organization and national authorities, there have been at least 41 confirmed cases outside China.
- Eight cases: Thailand
- Five: USA
- Four: Singapore, Australia, Taiwan, Malaysia
- Three: France, Japan
- Two: South Korea, Vietnam
- One: Nepal, Canada
Almost all had recently been to Wuhan.
The virus itself is a new, or “novel” coronavirus – a family that normally affects animals.
One human variant causes the common cold – but another variant, Sars, killed hundreds in a major outbreak in 2003.
‘The symptomless spreaders’
The news that this virus can spread during the incubation period is a significant development in our understanding of the virus – and the lengths China will have to go to, to stop it.
People with Sars (the last deadly coronavirus outbreak to hit China) and Ebola are contagious only when symptoms appear.
Such outbreaks are relatively easy to stop – identify and isolate people who are sick and monitor anyone they came into contact with.
Flu, however, is the most famous example of a virus that you spread before you even know you’re ill.
We are not at the stage where people are saying this could be a global pandemic like swine flu.
But stopping such “symptomless spreaders” will make the job of the Chinese authorities much harder.
There are still crucial questions – how infectious are people during the incubation period, and did any of the patients outside China spread the disease in those countries before becoming sick?
Learn more about the new virus
Are you in China? Have you been affected by the lockdown in various cities? Email.
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways: