The H5 infectious strain of bird flu has now been found at a poultry farm in Gelderland, bringing the total number of confirmed cases on Dutch farms to seven.

Some 48,000 hens on the farm in Boven-Leeuwen are being destroyed, as are 240,000 hens on three other farms less than a kilometre away. Samples are being taken at six other farms with a three kilometre radius of the infected site.

The H5 virus was first identified in a number of dead wild ducks in November and was then confirmed at several duck farms in Biddinghuizen, in the heart of Flevoland. Over 200,000 ducks and nearly 400,000 hens have so far been killed in an effort to stem the spread of the disease.

All poultry farmers, zoos and private owners have been ordered to keep their birds indoors because of the risk of spreading the disease. Officials have also introduced a ban on bird shows and on hunting ducks and geese.