France, Oct. 22 -- France raised its bird flu alert to the highest level on Wednesday after a rise in new cases in poultry and backyard flocks, triggering stricter biosecurity rules including the confinement of birds.

A government decree in the Journal officiel confirmed the risk level will move from "moderate" to "high", the top tier in the national alert system.

The move means poultry must now be sheltered and protected from contact with wild birds - an early precaution compared with previous years.

Authorities said the decision was prompted by "the dynamic spread of highly pathogenic avian influenza (HPAI) in migratory flyways crossing France", with new cases detected among migratory wild birds on French territory.

Officials warned...