The Finnish food authority said on Tuesday it has ordered 50,000 farmed mink and foxes to be culled at three fur farms hit by avian influenza infections as mink can host the virus, increasing the chance of it mutating and affecting humans, reported Reuters.

Finland and Norway are facing record outbreaks of the H5N1 virus strain this year. The virus has killed thousands of seagulls and other bird species, put livestock at risk and restricted travel in some areas.

"Mink is an especially problematic species when it comes to avian influenza infections," the authority said, as it can be an effective intermediate host for avian influenza, enabling the virus to mutate more effectively into a form that will infect humans.

This year, avian influenza, commonly called bird flu, was found at 20 fur farms in Finland as of the end of July, with samples from another four farms currently being analysed, according to the food authority.

It said it was preparing further cull orders this week.