BEIJING, Nov. 6 (Xinhuanet) -- China's Ministry of Health Sunday gave a briefing on three pneumonia cases of unknown causes in Xiangtan County, central China's Hunan Province.

    Experts said they would not rule out the possibility of human infection of the deadly H5N1 bird flu, according to a spokesman for the ministry.

    The spokesman said: "Investigation is still under way."

    The ministry has invited experts with the World Health Organization to help ascertain the causes, the spokesman added. Enditem