France is set to cull about 600,000 poultry birds as the virus spreads among duck flocks in the southwest of the country, the farm ministry said.
France is among European countries - including Britain and Germany - to have reported highly contagious strains of bird flu late last year, leading to mass culls as authorities try to limit transmission from wild birds to farm flocks.
France has already slaughtered about 200,000 poultry and plans to cull a further 400,000 birds, a farm ministry official said.
