MANILA: The Philippines will cull at least 200,000 birds after confirming its first avian flu outbreak, but no animal-to-human transmission has been reported, officials said Friday.

Agriculture Secretary Emmanuel Pinol said he ordered the culling of all fowl within a kilometer (0.6 mile) of six affected farms in northern Pampanga province’s San Luis town.

The area has been declared a quarantine zone with a 7-kilometer (4-mile) surveillance area also established around the farms.

Pinol said he was informed Thursday that 37,000 birds have died from avian influenza subtype H5, which can cause illness and deaths in both animals and humans. Experts believe the ducks to be the virus carrier, he added.

He said he has informed President Rodrigo Duterte, the Department of Health and will report the outbreak to the World Organisation for Animal Health.

Pinol said farmers did not immediately report the deaths, which spiked in July, because they thought were from ordinary poultry disease.

Alene Asteria Vytiaco, an official of the Bureau of Animal Industry, said they will send samples collected from the farms to the World Organization for Animal Health and the Australian Animal Health Laboratory for further testing.