An official with the World Health Organization yesterday urged China to provide more virus sequence information of the H5N1 strain of bird flu to the international community.

China's Ministry of Agriculture shared five virus sequences last year, but this year it has only shared virus sequence information from an outbreak of wild birds in Qinghai Province, northwest China, which occurred in May, said Dr Shigeru Omi, WHO regional director for the Western Pacific Region.

China has reported six human cases of bird flu, including two fatalities, and more than 30 bird flu outbreaks this year.

Although there have been more than 30 reported outbreaks in domestic birds in 2005, none of those viruses has been made available to the international community so far, Omi told a news conference in Beijing after visiting central China's Hunan Province this week.

"The Ministry of Agriculture officials have told me that they understand the importance of sharing viruses, but time is of the essence," he said.

The ministry has not given a timeframe for providing the information, Omi said.

On Tuesday, the Chinese Center for Disease Control and Prevention gave two samples of human cases of H5N1 to WHO to help trace the virus' mutation and develop anti-retroviral drugs.

The two strains were isolated from the two fatalities from bird flu in east China's Anhui Province, said Dr Julie Hall, coordinator of epidemic alert and response in WHO's Beijing office.

WHO will seek more virus samples from other Chinese human cases in the provinces of Liaoning and Jiangxi and Guangxi Zhuang Autonomous Region from the Ministry of Health, she said.