HONG KONG/SINGAPORE, March 29 (Reuters) - Hong Kong and Singapore reported more cases on Saturday of a fast-spreading pneumonia that has killed 54 people worldwide as the United States urged Americans to postpone travel to parts of Asia.
But Vietnam played down the threat from the deadly virus and said the country was safe for visitors.
Severe acute respiratory syndrome or SARS has infected about 1,500 people globally. The World Health Organisation believes the disease, which has flu-like symptoms, started in China's Guangdong province last November.
As the number of cases grew, a Hong Kong health official said the infection could transmitted by air. "We've never ruled out the possibility that the disease might be airborne," said Director of Health Margaret Chan. An airborne virus will spread quicker than one carried by droplets.
Scientists say the virus is a new strain from the family of coronaviruses, which is the second leading cause of the common cold. For weeks now, they have said the virus is passed through droplets, such as in sneezing or coughing.
The Bank of China (Hong Kong) Ltd became the latest financial institution in the territory to announce it had shut a branch for two days from Saturday after an employee contracted the disease.
Hong Kong's Social Welfare Department also shut a floor at one of its district offices on Saturday for disinfection after one of its workers fell ill.
On Friday, banking giant HSBC Holdings and computer maker Hewlett-Packard shut some of their operations in the territory as an employee in each company was feared to have been infected.
With 11 people dead and 425 infected, Hong Kong on Saturday imposed stricter screenings on all arriving travellers.
The disease has killed 34 in mainland China and infected over 800, although authorities say the situation there is now under control. Four are dead in Vietnam, three in Canada and two in Singapore.
MOTOROLA WORKER INFECTED
The virus did little to dampen the mood at the Hong Kong Rugby Sevens, though the number of attendees on the opening day fell to over 15,000 from more than 24,000 last year.
"It's incredibly unlikely that I'll get it. It's only infected 425 people out of seven million (in Hong Kong)," said British publisher Lawrence Bell, who added he had no qualms about sharing beers with his friends.
In Singapore, mobile phone maker Motorola said one of its workers had been infected, causing it to pull around 530 production staff from the factory floor.
Motorola was informed on Thursday that a night-shift worker had contracted the virus. It asked the night-shift workers not to report to work as a precaution.
"A number of that total will be receiving the (quarantine) order. It's going to be a proportion of that total number," a spokeswoman for Motorola, the world's number two wireless phone maker, told Reuters.
The city-state has nearly doubled the number of people quarantined, ordering 1,514 citizens to stay home. It has shut schools for 10 days.
The number of people infected with the virus in the tiny state rose to 86 on Friday from 78 a day earlier, the government said. Those in serious condition rose to 12 from 11, it said.
Washington urged Americans to put off non-essential travel to mainland China, Hong Kong, Singapore and Hanoi to avoid outbreaks of the disease.
But Vietnam, where the virus has killed four medical workers and infected 62 people in Hanoi, says it is no longer a threat.
Speaking to a Pacific Asia Tourism Association conference, Vietnam Deputy Prime Minister Vu Khoan said the gathering underscored the view that Vietnam was a "safe and friendly destination."
"It's very clear that now this problem has been solved," Khoan told reporters after addressing the first big business meeting since the outbreak of the disease.
Deputy Minister of Health Nguyen Van Thuong said in an interview with state-run Vietnam Television: "The community is clean and there are no more threats."
Tourism is an important revenue earner for Vietnam, which saw 2.6 million foreign visitors last year.