Japan has initiated the culling of more than 2 lakh farm birds in Northern Hokkaido after reports of a contagious avian flu strain surfaced, AFP reported on Sunday. This is the country’s fifth major operation this winter to curb the spread of the virus detected in several farms.

Authorities had recently culled 5.5 lakh chickens in Niigata city, while 23,000 ducks were eradicated in Hokkaido’s Aomori prefecture. The transport of poultry and poultry products in the vicinity of the affected farms has been banned temporarily.

Officials said the operations were hindered by extreme temperature and snowfall. An unidentified official said, “We continued to cull the chickens today, but the work is difficult as the air temperature falls to -20°C at night.”

Japan’s last confirmed case of avian influenza was reported in January 2015.