Twelve people died in Hong Kong yesterday from the SARS virus, a record for a single day, and Singapore said the disease threatened to become its biggest crisis since independence.

China, where the virus is believed to have originated last year, intensified its newly declared open war on the disease by threatening to punish officials caught covering up cases.

The latest deaths took Hong Kong's toll to a world-leading 81 just a day after the territory's leader, Tung Chee-hwa, said the outbreak would "stabilise gradually".

It has now had 1,358 cases of Severe Acute Respiratory Syndrome, almost as many as on the Chinese mainland where the deadly virus first appeared in the southern province of Guangdong, the former British colony's neighbour.

The disease, which is fatal in about four per cent of cases and has no known cure, has killed 172 people and infected nearly 3,500 around the world.

Hong Kong was the first place SARS erupted outside the mainland and Singapore was not far behind as air travellers carried SARS around the world to infect people in 25 countries.

One of the infected was a male flight attendant with Cathay Pacific Airways Ltd, the first infected cabin crew member in Hong Kong.

Singapore said yesterday it may be facing the worst crisis since independence in 1965 as SARS threatens to wreak havoc on its economy.

Prime Minister Goh Chok Tong said his nation was having some success in limiting infection rates, but more needed to be done to tackle the climate of fear causing damage to the vital tourism and transport industries.

"If we fail to contain SARS in Singapore, it may become the worst crisis that our country has faced," Goh told a news conference. "The economic costs are huge."

That cost could top $850 million (Lm330 million), he said.

The threat of punishment from Premier Wen Jiabao was another sign China, accused of telling the world too little, too late about the outbreak of a new disease, was getting serious about SARS.

Newspapers, all supervised by the Communist Party or the government, gave prominent coverage yesterday to Wen's threats and his demand that officials at all levels come clean on SARS.

"Anyone who covers up SARS cases or delays the release of information will be harshly punished as this matter concerns the people's health and safety," the English-language China Daily quoted Wen as saying during a tour of schools on Friday.

That came shortly after the nine-man Communist Party Politburo Standing Committee, whose word is law, ordered an all-out war against SARS and full disclosure of the impact.

Yesterday, hundreds of thousands of its people fought back as folks from housewives to government officials armed with brooms and mops launched a city-wide clean-up campaign to battle the virus.

"Overall, the situation will stabilise gradually," chief executive Tung said on Friday.