The French government announced that tests on a wild duck found dead in the central-eastern Ain department confirmed the presence of the highly pathogenic strain of the virus.
It said containment measures were already in place.
Europe's largest poultry producer has ordered all poultry and tame birds to be kept indoors, and all farm ducks and geese to be vaccinated in three departments on the Atlantic coast.
Six member states of the European Union have now confirmed the presence of a strain of the virus potentially lethal to humans spreading across the continent after showing up in Turkey and central Europe.
Indian state government officials said a laboratory had confirmed the country's first outbreak of the virus in chickens after 50,000 birds died.
Iran said that 135 wild swans found dead at the Caspian Sea coast have tested positive for H5N1, the first cases of the virus to be confirmed in the Islamic republic.
Indonesia confirmed its 19th death from bird flu, a 23-year-old man who worked for a chicken vendor, as the health minister vowed to boost stockpiles of the Tamiflu anti-viral drug.
Indonesia has now reported eight fatalities from H5N1 this year alone, the highest figure globally.
The virus has claimed some 90 lives, mostly in Asia, since late 2003.