Wild birds swim in a lake in Salburua Natural Park near Vitoria, northern Spain, July 7, 2006. -Xinhua/AFP

Spain has recorded its first case ofH5N1 bird flu in a waterfowl outside the northern city of Vitoria, the country's Agriculture Ministry said on Friday.

The government department said the disease had been found in a great crested grebe in a marsh area. A protective zone with a three-km radius has since been set up.

Preventive measures, including banning outdoor poultry farming within a certain distance from some marshlands, had already been in operation in Spain, a country which is on a major route of migrating birds from Africa.

Bird flu has killed at least 131 people worldwide since it began ravaging Asian poultry in late 2003, according to the World Health Organization.

Experts fear that the highly pathogenic H5N1 strain might mutate into a form which could spread among humans.