The boy was admitted to a hospital in Phnom Penh on Tuesday with fever and respiratory symptom and died on Wednesday morning, said Ly Sovann, head of the health ministry's infections disease department.

The test results from the Pasteur Institute in Phnom Penh showed that the boy was infected with H5N1 bird flu virus, Ly added.

The boy's death brought total number of bird flu cases in Cambodia to six, or to two for this year only. A three-year-old girl from Kompong Speu province died of bird flu last month after playing with the sick and dead chickens.

The details on how the boy was infected with the deadly virus were not available now, the investigation is going on.

Cambodian Hun Sen blamed the death of the girl on lack of public information of the virus, and urged the country's media to increase coverage of bird flu information in an effort to effectively prevent the spread of the deadly virus.

Most Cambodian people killed by bird flu were from the provinces bordering Vietnam, which was the hardest hit country in the region.

According to World Health Organization figures, the virus has killed at least 108 people worldwide since late 2003, mostly in Asia. The WHO has warned countries not to be complacent because the disease is spreading in poultry and will spread around the globe.