Tiananmen Square is usually packed on May Day
China's traditionally important May Day celebrations have been hit by fears of the Sars virus, with many Beijing residents staying at home.
Streets that would normally be full of shoppers and holiday-makers were almost empty after the authorities cut the week-long holiday to a few days and issued strict travel advisories in a bid to stem the deadly virus' spread.
A few hundred people observed the traditional Labour Day flag-raising ceremony at Tiananmen Square on Thursday - an event usually attended by thousands.
Sars has already killed 170 people in China, and infected 3,647 others since it emerged in the southern province of Guangdong last November.
It has also spread throughout the world. As of Wednesday, 378 people had died from Sars and 5,600 had been infected.
Labour Day - one of the most important festivals in the Chinese calendar - is traditionally a time when Chinese people go home to their families.
Last year, more than 80m people travelled around the country on trains, buses and planes over the holiday period. But this year Beijing's travel terminals are practically deserted.
Known death tolls:
Mainland China: 348
Hong Kong: 298
Source: WHO/local authorities
In the past week, the capital has launched an intensive effort to contain the Sars virus, shutting schools, entertainment venues and a number of hospitals, as well as imposing strict quarantine measures.
On Thursday, a hastily built 1,000-bed Sars hospital was opened on the outskirts of Beijing, after being constructed in just eight days.
Despite all the precautions, another 11 new Sars fatalities and 187 cases of infection were reported in China on Thursday, more than half of them in Beijing.
On the outskirts of the Chinese capital, residents have set up barricades to keep out people who might bring Sars into their villages.
"We'll stay here and keep this roadblock up until the threat of Sars passes," one man told the Associated Press news agency.
Villages outside Beijing have built barricades to deter visitors
While the Sars virus continues to spread in China, other badly affected regions such as Hong Kong, Singapore and Canada have now got the outbreak under control, according to the World Health Organization.
But there was bad news from Hong Kong on Thursday, where doctors said that even those who recovered from Sars might have long-term or even permanent lung damage.
Twelve discharged patients have also experienced
relapses, according to doctors in the territory.
Meanwhile, Canadian doctors have cast new doubt on the origins of the Sars virus.
Speaking at a Sars conference in Toronto, they said they had found evidence of the coronavirus - believed to cause the disease - in less than half of their Sars patients.
Two weeks ago it seemed that the cause of Sars had been firmly identified.
If the current policy of isolating and quarantining patients is unable to contain Sars, drugs and vaccines will be needed - and for that scientists will need to know precisely which virus they are developing drugs and vaccines against, says BBC science correspondent Richard Black.