Hundreds of thousands of birds will be slaughtered in the Philippines as the country experiences its first avian flu outbreak for the year. Agriculture Secretary Manny Piñol has confirmed at least 400,000 chickens, quails and ducks will be culled to prevent the outbreak spiralling out of control.

Piñol said the flu first was first reported in a quail farm in April and since then 37,000 birds have lost their lives in the province of Pampanga, north of Manila.

"We will cull all 400,000 birds within a 1-km (0.6 miles) area. We don't want diseases to spread," Piñol told reporters. Precautions have already been taken to check whether there is any human transmission though none has been reported so far. The slaughter of the caged birds is set to begin on Friday, 11 August.

Health experts are examining the origins of the disease whether the flu was carried by migratory birds or through illegal bird smuggling from countries like China. The government's agricultural department is set to hold a media briefing shortly.

Even though there were indications that the birds could have been affected by the disease in May, poultry operations showed reluctance to report the development. However, the situation worsened in the coming weeks forcing authorities to go for the mass culling.

"We really have to do it (extermination of fouls) because we don't want the disease to spread. I already ordered our quarantine department to set up quarantine stations in the area," added Piñol.

While President Rodrigo Duterte has already been informed of the situation, the government has promised to submit a detailed report to the World Organisation for Animal Health.