The World Health Organisation (WHO) has said the massacre of an estimated 25 million chickens in 10 affected nations could in fact aggravate the epidemic unless it was carried out safely and fairly.

"If the killing of birds is done in such a way that exposes more people, then this…could be increasing the risk of developing a strain that you would not want to see," said WHO spokesman Dick Thompson.

WHO fears unsafe culling could lead to a more disastrous mutation that would enable the deadly H5N1 strain of bird flu to be transmitted from person to person.

Lurking dangers

"From what we can see…many of these culling workers are not wearing the right personal protection equipment, we are also unsure how many of these people have been vaccinated against normal influenza," Thompson said.

WHO has warned that while humans have so far only caught the disease through contact with infected birds or their droppings, it could claim millions of lives if it mutates into a more contagious form.

The United Nations Food and Agriculture Organisation (FAO) also said it was vital to properly compensate poultry farmers whose flocks were destroyed.

"If the killing of birds is done in such a way that exposes more people, then this…could be increasing the risk of developing a strain that you would not want to see"

Dick Thompson
WHO spokesman

"Compensation will be one of the key factors that will determine whether or not we stamp out these outbreaks," FAO's Bangkok-based regional animal health officer Hans Wagner said.

"If the level of compensation is insufficient then the farmers will not carry out the culls. They may even resort to clandestinely selling the infected animals," he said.

The latest warnings come amid increasing panic over the rapidly spreading epidemic already affecting ten Asian countries.

The virus has claimed 10 lives, eight in Vietnam and two in Thailand, which on Friday reported four new suspected cases.

WHO recommends that all birds within a radius of three kilometers of any outbreak be killed.

In Thailand alone 10.7 million chickens have been killed, mostly packed into sacks and buried alive in hastily dug deep pits.