China has quarantined millions of people and urged its citizens to delay overseas travel as it scrambles to stop a deadly coronavirus epidemic from spreading further.

Authorities also ordered schools and universities to remain closed on Tuesday after extending a national holiday by a week in a bid to contain an outbreak that has already killed more than 100 people and spread to a dozen countries.

Earlier the government shuttered major tourist attractions from Disneyland to a stretch of the Great Wall and rolled out draconian transport restrictions in areas worst affected by the virus.

Here is a rundown of the measures taken so far in an unprecedented effort:

With people rushing to get masks at pharmacies and on popular websites, China's industry and information technology ministry vowed to increase supply
With people rushing to get masks at pharmacies and on popular websites, China's industry and information technology ministry vowed to increase supply AFP / NICOLAS ASFOURI

More than 56 million people are subject to travel curbs in Hubei province, where the virus was first detected.

Public transport has been stopped in 18 cities there, with train stations shut, events cancelled and theatres, libraries and karaoke bars closed in some locations.

The epicentre of the outbreak is provincial capital Wuhan, the biggest city on lockdown, where the government has halted all travel out of the Yangtze River metropolis of 11 million.

Wuhan residents have been told to stay home and authorities have restricted car traffic in the city centre.

Similar quarantine measures are being taken in nearby cities, with strict controls on weddings and funerals, temperature screenings for new arrivals, and the suspension of online taxi services.

Beijing, Shanghai and other megacities have suspended the entry and departure of long-distance bus services and mMore than 400 inter-province train services were cancelled
Beijing, Shanghai and other megacities have suspended the entry and departure of long-distance bus services and mMore than 400 inter-province train services were cancelled AFP / NICOLAS ASFOURI

Beijing, Shanghai and other megacities have suspended the entry and departure of long-distance bus services.

At least 2,000 inter-province train services have been cancelled since Friday -- most until February 8-9 but some for weeks.

China's immigration agency has also asked citizens to delay international travel to stop the virus from spreading elsewhere overseas.

China has quarantined millions, urged citizens to delay overseas travel, ordered schools and universities to stay closed, extended a national holiday and closed major tourist attractions to try and contain the virus
China has quarantined millions, urged citizens to delay overseas travel, ordered schools and universities to stay closed, extended a national holiday and closed major tourist attractions to try and contain the virus AFP / NICOLAS ASFOURI

Authorities had already suspended both domestic and overseas Chinese group tours over the weekend.

Tourists from Hubei in Haikou, capital of the island province of Hainan, were told by the city government they had to spend 14 days in a hotel for centralised medical observation, and were forbidden to leave.

Hundreds of millions of people criss-crossed the country last week return to their families for the Lunar New Year holiday, in what is typically a joyous time of gatherings and public celebration.

Instead, public health officials asked China's 1.4 billion citizens to confine themselves at home until all is clear.

Authorities in Wuhan are rushing to build two field hospitals by next week to ease pressure on medical facilities in the city that are struggling to handle a growing caseload
Authorities in Wuhan are rushing to build two field hospitals by next week to ease pressure on medical facilities in the city that are struggling to handle a growing caseload AFP / Hector RETAMAL

Schools and universities across the country were ordered not to reopen until further notice on Tuesday, a day after the holiday break was extended to try and reduce the spread of the virus.

Wuhan and Beijing had earlier cancelled public events that usually attract hundreds of thousands of people to temples during the New Year holiday.

The historic Forbidden City -- a sprawling imperial palace in Beijing and one of the country's most revered cultural sites -- was closed from Saturday.

Other famous landmarks including a section of the Great Wall, the Ming Tombs and Yinshan Pagoda are also not open to visitors. Tibet's Potala Palace was shut down on Monday.

Disneyland theme parks in Shanghai and Hong Kong have closed down indefinitely.

Women's Olympics football qualifiers scheduled for next week in Wuhan have been moved out of the country and will now be held in Sydney.

China's film box-office earnings for Lunar New Year's Eve on Friday were just one-tenth of last year as people shunned crowds.

US coffee chain Starbucks said it had shut all its stores in Hubei during the holiday break.

China has ordered sterilisation and ventilation at airports and bus stations, as well as inside planes and trains, while travellers are being screened for fever.

Temperature screening checkpoints have been set up in hundreds of Chinese railway stations, according to state news agency Xinhua.

Authorities have asked people to wash their hands regularly, avoid crowded places, get plenty of fresh air and wear protective face masks.

City authorities in Wuhan have gone further and made it mandatory to wear masks in public places. A similar order was issued in southern Guangdong province, which has more than 110 million people.

With people rushing to get masks at pharmacies and on popular websites, China's industry and information technology ministry vowed to increase supply.

Authorities in Wuhan are rushing to build two field hospitals by next week to ease pressure on medical facilities in the city that are struggling to handle a growing caseload.

The first facility is expected to be operational by next Monday and will have a capacity of 1,000 beds spread over 25,000 square metres, according to state media. The second is slated to open two days later with 1,300 beds.

Xinhua said the two new hospitals in Wuhan would be similar in size to the temporary facility built to tackle SARS in Beijing in 2003, when 650 people died from the disease in the mainland and Hong Kong.