The government of reclusive Turkmenistan, which insists that the Central Asian country has never had a single coronavirus case, recommended on Monday that residents wear masks because of "dust".
It also requested that people in the tightly-controlled country maintain a social distance of at least one metre (three feet), without giving an explanation as to why.
The announcement came after a World Health Organization delegation arrived in Turkmenistan last week for a 10-day mission examining the country's response to the pandemic.
Turkmenistan -- a tightly-controlled, oil-rich, ex-Soviet state -- is one of the few countries in the world yet to declare any coronavirus cases.
In a statement published by the state information agency on Monday, the health ministry said people should wear masks because of "high concentrations of dust" in the air.
"It is strongly recommended that everyone use personal protective equipment to protect the upper respiratory tract," the ministry said.
Officials also asked Turkmens not to stand too close to air conditioners after spending time outside, in a country where summertime temperatures regularly exceed 40 degrees Celsius (104 degrees Fahrenheit).
The World Health Organization did not immediately respond to an emailed request for comment on the statement.
- Temperature checks -
Few people were wearing masks on the streets of the capital Ashgabat, where the largest bazaar was closed for disinfection Monday.
Two other markets were only allowing people wearing masks to enter. Customers were given temperature checks on entering -- a measure rarely required for large amounts of dust, but one regularly used worldwide to identify COVID-19 infections.
A 28-year-old man, who gave his first name, Nuri, told AFP that he had been surprised when traffic police pulled him over him and threatened to fine him for not wearing a mask.
"(The road policeman) decided not to fine me in the end," after he found a mask in his car and put it on, Nuri said.
Baili, a 42-year-old woman who works as a civil servant, said officials had asked all government employees to wear a mask, but did not mention coronavirus as a justification.
"They told us that this is advised by the Ministry of Health, because there are a lot of sick people in the world due to poor ecology," Baili told AFP.
"They gave masks to everyone in the organization and we were told to wear them all day."
Drivers of public transport and taxi services donned facial protection for the first time last Monday as the WHO delegation arrived.
Police had previously been seen discouraging citizens from wearing masks and face coverings were absent at mass government events held in recent months, some of which were attended by thousands of people.
The WHO in June began recommending that people wear masks on public transport and in other situations where physical distancing not possible.
Last month the foreign ministry dismissed as "fake news" a US embassy health alert warning Americans over potential coronavirus cases in Turkmenistan.