The World Health Organisation (WHO) urged China to take swift action to contain bird flu as new suspected outbreaks of the disease, which has killed 10 people in Vietnam and Thailand, were reported in the central province of Hubei and southern Guangdong.

But in a reminder that China is yet to bury the ghost of Severe Acute Respiratory Syndrome (SARS), the Ministry of Health announced that a 40-year-old doctor had become the fourth person infected in recent weeks.

The patient has already been discharged from hospital in the southern province of Guangdong, where SARS is thought to have originated before spreading abroad and killing 800 people worldwide last spring, the ministry said on its website.

The other three confirmed cases this winter, also from Guangdong, have also been treated and released.

The WHO urged China to learn the lessons of SARS by taking swift action to contain avian influenza, which is suspected or confirmed in six provinces and municipalities.

"We have repeatedly said there is a brief window of opportunity to act within China," said Julie Hall, a Beijing-based WHO infectious disease expert.

"This latest news strongly suggests that the window is getting smaller with each passing day," she said in a statement.

The two new suspected outbreaks, in Ezhou city of Hubei province and Chao'an county of Guangdong province, brought the total number of suspected cases to six in China in the past 24 hours. Three other outbreaks have been confirmed as bird flu.

Suspected or confirmed cases have also hit the most populous city, Shanghai, and Anhui province in east China, Hunan and Hubei provinces in central China and Guangxi and Guangdong provinces in southern China.

President Hu Jintao expressed confidence China can defeat bird flu.

"Even though now we are seeing new cases discovered ... I think we are confident we can solve the problem well," Hu told the Hong Kong-based Phoenix TV during his ongoing visit to Egypt.

Officials imposed a ban Saturday on poultry exports from Shanghai, Anhui as well as Guangdong, which is one of China's top three poultry-producing provinces. Exports from the other regions were banned earlier this week.

China's poultry industry -- which produced 9.8 million metric tonnes of poultry in 2003, making it the second largest producer in the world, according to US figures -- could face severe economic losses.

Hong Kong -- a major market for neighboring Guangdong -- banned poultry from all parts of mainland China Friday, and Japan, China's largest broiler market, also banned Chinese poultry this week.

To contain the disease, poultry was being culled in areas of suspected outbreaks and poultry workers were being quarantined, officials told AFP.

"In six to seven hours, we've killed 35,000 chickens," said Yang Ping, an official in Anhui province, where dozens of chickens died this week in a farm.

Xu Shengwei, a farmer from the Shanghai farm affected, described the devastation.

"I noticed they weren't eating properly. The next day, I suddenly found 200 dead ducks in a pen," Xu recalled.

China this week ordered the culling of all poultry within a three-kilometer (two-mile) radius of affected farms. Hundreds of thousands of birds are estimated to have been killed, with 1.3 million culled in Hunan alone.

No human cases of bird flu have been reported in China.

Carrier pigeon races were banned in several cities on Saturday.

The WHO, which has warned the outbreak in China could be far worse than reported, urged China to step up surveillance and employ the same stringent measures used to combat the nationwide outbreak of SARS last year, which began in Guangdong, killing 349 people in China and nearly 800 worldwide.

The WHO also appealed to China to share full details of its poultry vaccination programs, suspected of causing the Asia-wide outbreak, and to ensure workers carrying out the culling are properly protected.

TERRA.WIRE