MANILA, Philippines (AP) — The Philippines will cull at least 400,000 birds after confirming its first bird flu outbreak, but says no animal-to-human transmission has been reported.

Agriculture Secretary Emmanuel Pinol says he has ordered all fouls within a kilometer (0.6 mile) of six affected farms in northern San Luis town culled. He says the area has also been declared a quarantine zone.

Pinol says he was informed Thursday that 37,000 birds have died from subtype H5 avian influenza after infections started in a quail and duck farm. He says experts believe the ducks to be the virus carrier.

He says he has informed President Rodrigo Duterte, the Department of Health and the World Organization for Animal Health about the outbreak.