Mongolia - which has not confirmed any infections - has suspended all flights from Japan, adding to previous restrictions on flights from China and South Korea. It has also extended a travel ban on people from Japan and South Korea until March 11.

It will also take precautions with other flights from Europe, Russia, Turkey and Kazakhstan, Enkhamgalan Byambasuren, the transportation minister, told reporters.

Combating infectious disease is a particular challenge for Mongolia’s vast and thinly populated steppe, which lacks hospitals and even basic infrastructure.

The country has already sealed off its border crossings from China and suspended schools until the end of March.

Mongolia has also extended its suspension of coal deliveries into China until March 15. The suspension was originally due to come to an end on March 2.

Enkhamgalan said the drastic restrictions on internal movement were introduced after a Vietnamese citizen suffering from a fever was found to have travelled to the Bayan-Ulgii province on Tuesday. Five people are now under quarantine.

“There is likelihood the disease can spread to other parts of Mongolia,” he said.

Mongolians will now need to get specific permission from the head of their local emergency commission to travel out of Ulaanbaatar, city mayor Amarsaikhan Sainbuyan said on Wednesday.

He added that the car registrations and identity card numbers of travellers would be added to a database to help track potential sources of infection.

Ulaanbaatar was also considering restricting activities at monasteries, churches, restaurants and bars, the mayor added.

He said they would pay particular attention to the 28 Korean churches operating in Mongolia, and check whether any South Korean citizens working in Ulaanbaatar had recently travelled back from their home country.

South Korea has a total of 1,216 confirmed cases of infection so far, the highest outside China, and is to test more than 200,000 members of a church hit hardest by the outbreak. (Reporting by Anand Tumurtogoo; Writing by David Stanway; Editing by Andrew Heavens)