Singapore/Kuala Lumpur: "Do not wear a mask if you are well" read a warning plastered across the front of Singapore's main newspaper on Friday, as authorities around the world sought to calm panic buying of masks seen as a guard against the fast-spreading coronavirus.
In neighbouring Malaysia, the government urged people to always have masks and hand sanitisers ready, similar to advice by authorities in Thailand and Vietnam.
Conflicting messages have sowed confusion over how to protect against an epidemic that has claimed over 200 lives in China and spread to over 20 countries, with some experts saying wrong handling of masks could even increase infection risk.
"Wearing a mask only when u feel unwell? Then why do u need soldiers when there isn't war? It's better to be safe than sorry" Facebook user Kenny Chan Wai Kong posted in Singapore, where authorities have announced plans to give four masks to every household as retailers' stocks run dry across the island.
In parts of Asia, wearing face masks is common when people are sick or to counter urban pollution.
Official guidance from the World Health Organisation and the Centre for Disease Control and Prevention makes no mention of wearing a face mask as a preventative measure against the virus - but their websites do not specifically advise against them.
Australia and Taiwan have said healthy people don't need masks, but Australia has released 1 million masks from the national medical stockpile, and masks are widely worn in Taiwan's capital Taipei where the government has imposed purchase limits and an export ban on masks.
The Taiwan Railway Administration said on Friday that if the virus continues to spread it will refuse to carry passengers not wearing masks.
Masks must be fitted correctly
Coronavirus can be transmitted from person to person, although it is not clear how easily. Most cases have been in people who have been in the Chinese city of Wuhan at the centre of the outbreak, family members of those infected, or medical workers.
Transmission is likely through contact with an infected person via particles in the air from coughing or sneezing, or by someone touching an infected person or object with the virus on it and then touching their mouth, nose or eyes.
"Situations that require a mask are when you are in a crowd...or if you are caring for a sick person. If it makes you feel better, wear a surgical mask," Angela Rasmussen, virologist at the Center for Infection & Immunity at Columbia University said on the Reuters Global Markets Forum.
Other experts have said disposable surgical masks may not fit the face tightly enough to prevent infection, while some have pointed out that wrong handling of masks such as touching the front could increase the likelihood of infection spread.
In Hong Kong, a lawmaker who chairs the city's government health services panel was slammed over a short video she posted showing people how to steam and re-use disposable face masks.
More unusual advice has seen India's government suggest a traditional concoction that includes ginger and holy basil as virus protection, while a Myanmar minister was rebuked for sharing a Facebook post that advised people to eat more onions.
Some overseas Chinese have been buying masks to send to friends and relatives in China, where some stocks have been running out. Chinese citizens living in Vietnam, Thailand and Malaysia sent 150,000 masks back to their home province of Gansu on Thursday, China's Xinhua news agency reported.
In China, where nearly 10,000 cases have been reported so far, Zunyou Wu, chief epidemiologist at the Chinese Center for Disease Control and Prevention, told state broadcaster that people need to wear masks when taking public transport.