China has lifted a bird flu quarantine in southwestern province of Guizhou on Tuesday after no new cases were reported for 21 days.

No new outbreaks of the deadly H5N1 bird flu virus strain were found 21 days after at least 240,000 poultry have been slaughtered since it broke out on February 17 in Zheng'an County, Zunyi City in Guizhou, the Ministry of Agriculture said on Tuesday.

The ministry has urged local authorities to beef up supervision and prevention measures and raise people's awareness to prevent new outbreaks.

Bird flu, or Avian influenza, is a contagious disease of animal origin caused by viruses that normally infect only birds and, less commonly, pigs. It can kill humans.

China saw five bird flu outbreaks in poultry this year. Others included one in the northwestern Xinjiang Uygur Autonomous Region, two in the southwestern Tibet Autonomous Region and one in the southern Guangdong province.

On February 25, a 44-year-old woman surnamed Zhang in Haifeng County in Guangdong, was killed by the H5N1 strain of the bird flu virus. This raised the total number of human bird flu cases recorded in China to 29, of which 19 have been fatal, according to the World Health Organization.

The ministry earlier this month warned that the country faced a more "complicated" epidemic control situation this year with a rise in the number of reported cases.

(Xinhua News Agency Mach 19, 2008)