Hundreds of birds were culled in India's southern state of Kerala where a district has seen a surge in the number of bird flu or avian influenza cases, local health officials told Reuters partner ANI.

After an outbreak last week in broiler chickens in two villages in Kottayam district, authorities have culled hundreds of ducks and other domestic birds, district veterinary doctors said.

On Sunday, farmers were seen catching ducks in shallow ponds and handing them over to health officials to be taken to a designated area for culling.

"We started the culling operation of different domestic birds in an area of one-kilometre (0.62 mile) radius around the infectious ponds," Shaji Panikar, Kottayam's veterinary head, said on Monday.

The spread of the virus is a concern for governments and the poultry industry due to the devastation it can cause to flocks, the possibility of trade restrictions and a risk of human transmission.