A two-year-old Cambodian girl has died from bird flu, becoming the country's fourth confirmed fatality -- all children -- from the deadly virus this year, health authorities said Monday.

The girl from the southern province of Kampot died on Friday a day after she was admitted to hospital, the health ministry said in a joint statement with the World Health Organisation (WHO).

Tests confirmed she had contracted the H5N1 virus, it said, adding the girl had direct contact with dead chickens in a village where most of the poultry had perished over the last few weeks.

Health Minister Mam Bunheng urged parents to ensure their children do not touch birds.

"Avian influenza H5N1 remains a serious threat to the health of all Cambodians and more so for children," he said in the statement.

The disease typically spreads from birds to humans through direct contact. But experts fear it could mutate into a form easily transmissible between humans, with the potential to trigger a pandemic.

Authorities have struggled to control bird flu outbreaks in Cambodia. It recorded 14 deaths from the illness last year, the deadliest outbreak of the virus in the country since 2003.

Cambodian children are at particular risk as they often live in close proximity to poultry.

Two boys, aged 3 and 11, died of bird flu earlier this month.

An eight-year-old boy from the eastern province of Kratie died in February. His two-year-old sister died the same day but authorities said tests could not be carried out to confirm she had the virus.

The sickness has killed nearly 400 worldwide since a major outbreak in 2003, according to the WHO.