The outbreak was found at a farm of about 13,000 turkeys in Beaufou in the Vendee department, Anvol Director Yann Nedelec told Reuters.

"This means that there is a new area hit," Nedelec said, stressing that the region was vulnerable to avian influenza outbreaks as it hosts a large number of poultry farms and is under some migrating birds' corridors.

Avian influenza is often carried by wild birds in the autumn and winter.

It has been spreading quickly in Europe in recent months, putting the industry on alert after previous outbreaks led to the culling of tens of millions of birds.

So far this season the virus has already killed more than 600,000 poultry in France, Nedelec said.

A first farm case in France had been detected on 26 November on a poultry farm in the north,

Outbreaks in north were now under control, Nedelec said.

However, the virus was still spreading among duck farms in the foie gras production zone of the southwest, where flocks were decimated by outbreaks last winter.

"Hopefully it won't be as bad this year, looking at the strict measures we have taken, including keeping all flocks indoors," Nedelec said.

In Italy, data from the World Organisation for Animal Health (OIE) show nearly four million birds died in the country because of avian influenza between mid October and 26 December.

Avian influenza cannot be transmitted through the eating of poultry products. But outbreaks are raising concern among epidemiologists because it can be transmitted from one human to another.