Jakarta, Indonesia ? The World Health Organization might soon convene an expert panel to decide whether an unprecedented human outbreak of bird flu in Indonesia requires the world to go on higher alert for a possible pandemic, health officials said Wednesday.

If the global alert status were increased, international stockpiles of antiviral drugs would probably be shipped to Indonesia and travel from the country would be monitored to contain the outbreak.

Indonesian health authorities this week confirmed that the virus had killed at least six members from a single extended family on Sumatra island, including the death Monday of a 32-year-old man. A seventh family member also died from what investigators suspect was bird flu, but she was buried before samples could be taken. Another relative is hospitalized with a confirmed case.

Maria Cheng, a WHO spokeswoman in Geneva, said the outbreak in the North Sumatran village of Kubu Sembilang, was not only the largest bird flu cluster in the world but also the first in which investigators believe the virus was passed from one person to another and then to a third.

While the outbreak is exceptional, international and Indonesian health officials in Jakarta stressed that the virus appears unchanged. Laboratory analysis of virus samples shows that it has not mutated or developed into a form more easily passed among people.