Phnom Penh, Feb 09: A pregnant 24-year-old Cambodian woman who died last week in a Vietnamese hospital could have fallen victim to the bird flu virus, officials said today. ''We are closely following her as a suspected case,'' said Sean Tobin, a World Health Organisation official in the Cambodian capital Phnom Penh. ''From what we know from local officials, her case is certainly suspicious enough to be suspected.'' Officials at Chau Doc hospital in Vietnam said the woman died on Friday of acute respiratory illness, adding that the Pasteur Institute in Ho Chi Minh city was running tests to determine the exact cause of death, suspected to be avian influenza. Eighteen people have so far been confirmed as dying of bird flu in recent weeks - 13 in Vietnam and five in Thailand. Bureau Report