The Malaysian Government is not allowing its nationals to return home from abroad if they show symptoms of the flu-like illness known as Sars which has killed about 90 people worldwide.
Malaysia: Spread of virus treated as issue of national security
After confirmation of Malaysia's first death linked to the outbreak, Health Minister Chua Jui Meng said Malaysians travelling abroad must first be cleared by doctors in the countries they are visiting.
Elsewhere, China has announced several more deaths from the virus, taking the total above 50 people dead there.
They include China's first foreign victim - a Finnish man who died in a Beijing hospital.
In Australia, the authorities are to be given the power to quarantine anyone suspected of suffering from the potentially deadly virus
Under the new precautionary measures, both Australian citizens and airline passengers entering the country can be detained for medical assessment and, if necessary, forcibly treated if they have the disease.
And on Sunday, the biggest hospital in Singapore started screening visitors after 20 of its nurses and a doctor were suspected of contracting the Sars virus.
Chinese officials, striving hard to address criticism over their secretive handling of the pneumonia-like virus, hastily convened a news conference on Sunday to announce the death of Pekka Aro. The 53 year-old Finn, who was working for the International Labour Organisation, was thought to have travelled to Beijing from Thailand.
SARS: PROBABLE CASES AND DEATHS
China 1247 cases (51 deaths)
Hong Kong 842 (22)
Singapore 103 (6)
Vietnam 60 (4)
Canada 74 (8)
Thailand 7 (2)
Malaysia (suspected) 70 (1)
Source: National health authorities
Chinese officials have been trying to limit the damage done by Beijing's secretive handling of the issue.
The BBC's Francis Markus in Shanghai says China is extremely concerned that Sars could hurt its image and the flow of foreign investment.
Staff at Shanghai's international airport said they wanted to wear face masks like their counterparts in Hong Kong, but were ordered not to because it would look bad.
In the Chinese territory of Hong Kong, two more deaths were reported in Hong Kong and 42 new cases of Sars, bringing the total number of cases there to more than.
A Hong Kong man who refused to be treated for the virus was locked in a 14-hour standoff with police in his apartment before eventually being persuaded to seek treatment, authorities said on Saturday.
Correspondents said Hong Kong remains concerned about further spread because of Saturday's important Ching Ming festival when residents traditionally go to southern China to visit their ancestors' graves.
Outside Asia, the worst-affected country is Canada, where at least 74 people have contracted the illness.
In the US, President George W Bush has issued an executive order allowing the forced quarantine of patients with Sars if deemed necessary by the health secretary.
Pakistan said on Sunday it would quarantine anyone from affected countries suspected of being infected with Sars.
Breakthrough in prospect?
China has promised to release more information on the pneumonia virus which emerged in the southern Guangdong province last November, before spreading to Hong Kong and around the world in March.
But it has come under fire for failing to report early and openly on the disease.
Deputy Prime Minister Wu Yi called for "the immediate establishment of a national medical emergency mechanism, with emphasis placed on a public health information and an early warning reporting mechanism".
A team from the World Health Organisation (WHO) visiting the province has urged Chinese authorities to re-examine samples taken from victims killed by the virus.
They want to see whether the illness might involve multiple viruses or bacteria.
WHO officials have told the BBC they hope to make a breakthrough on the virus in "weeks rather than months".
The WHO believes the epidemic Guangdong appears to be under control while an outbreak in Singapore could be almost over.