France has raised its risk level of avian influenza to 'moderate' from 'negligible', Reuters reported, citing a decree published in the official journal on Tuesday, a move that will reinforce security measures around poultry farms.

The ministry said the change in status was linked to a rise in the number of cases of highly pathogenic avian influenza in several neighbouring countries, raising the possibility of migratory birds passing on the virus while passing through France.

A growing number of European countries have reported cases of the virus that has killed millions of poultry in previous outbreaks, including Germany.

France has reported four bird flu outbreaks on farms since the summer and launched a second vaccination campaign among farm ducks of more than 250birds at the start of the month after a successful inaugural programme last year.