31-year-old woman has died of bird flu in northwest China´s Xinjiang Uygur Autonomous Region, becoming the fourth death from the disease in the country so far this year, the local health department said Saturday.

    The woman surnamed Zhang, a resident in the regional capital Urumqi, died at 4:40 a.m. Friday. She had been to a poultry market before she fell ill on Jan. 10, said Wang Xiaoyan, deputy director of the regional health department.

    She was confirmed to have been infected with the H5N1 strain of avian influenza by the Chinese Center for Disease Control and Prevention on Saturday.

    People who had close contact with Zhang have not shown symptoms of infection yet, said Wang. The official did not give the exact number of these people.

    Three others died of bird flu and another has been infected in the country so far this year. The first death was a 19-year-old woman in Beijing on Jan. 5, followed by a 27-year-old woman in Shandong on Jan. 17 and a 16-year-old boy in Hunan on Jan. 20.

    A 2-year-old girl who was critically ill with the disease was out of danger at a hospital in Shanxi on Friday after her vital signs remained stable for six consecutive days.

    The death rate for bird flu patients is above 60 percent.

    The country has warned of an even more challenging situation in preventing the disease from spreading in face of a mass migration, mostly of migrant workers and students, for the traditional Spring Festival, or Lunar New Year, which falls on Jan. 26.

    The Urumqi city government has set up a task force to prevent and control the virus. It also launched a daily epidemic surveillance and reporting system.