TAIPEI - Two poultry farms in Taiwan's Yunlin County, a major chicken supplier on the island, were confirmed to be infected with the H5N2 bird flu virus, leading to a culling of more than 30,000 birds, the local animal inspection authority said Tuesday.

More than 4,000 birds on a farm in Cihtong Township were killed Tuesday after its chickens tested positive for the H5N2 virus in late March.

Another farm in Yunlin's Douliu City was also confirmed to have the virus after more than half of its 56,000 chickens died in one week. The local inspection authority decided to cull the remaining birds Tuesday afternoon.

A large temperature difference has led to a rise in bird flu infections, according to the local animal inspection authority. It also warned farms to strengthen quarantine and sanitation work and report any unusual deaths of poultry in a timely manner.

A total of 117 poultry farms have been infected with highly pathogenic avian flu viruses across Taiwan since the beginning of this year, with 62 of the farms in Yunlin.