The Dutch authorities on Saturday ordered the preventative cull of 8,000 ducks amid fears that a bird flu outbreak could spread to the country's poultry heartland.

"In Barneveld 8,000 ducks will be culled as a precautionary measure," the economics ministry said in a statement after the highly pathogenic H5N8 strain was confirmed on two other farms near The Hague to the southwest.

A farm at Kamperveen to the northeast of Barneveld, one of Europe's most intensive poultry farming regions, has also been confirmed to have bird flu, although it is not known if it is the highly pathogenic variety previously detected only in Asia.

Two other farms around Kamperveen are suspected to have been infected.

Saturday's cull was ordered because "a truck that visited the infected duck farm in Kamperveen visited the farm in Barnveld," the ministry said.

Junior economics minister Sharon Dijksma said that she "did not want to take any chances given the duck farm's location in the concentrated poultry farm area of Barneveld."

An outbreak of the H7N7 strain of avian flu in 2003 severely hit the Netherlands with health authorities destroying some 30 million birds.

Switzerland on Friday said it was banning chicken imports from the Netherlands and Britain, where there has been a similar H5N8 outbreak at a duck breeding farm in Yorkshire.

Belgium has ordered poultry owners to confine their birds as a precautionary measure following the outbreak in the Netherlands.

Some strains of avian influenza are fatal for chickens, and pose a health threat to humans, who can fall sick after handling infected poultry.

The H5N1 strain of bird flu has killed more than 400 people, mainly in southeast Asia, since first appearing in 2003.

Another strain of bird flu, H7N9, has claimed more than 170 lives since emerging in 2013.

There are some 95 million chickens on Dutch poultry farms and egg exports totalled some 10.6 billion euros ($13.2 billion) in 2011, according to the latest Dutch statistics.

Switzerland bans Dutch poultry imports, new bird flu cases in Holland
The Hague (AFP) Nov 21, 2014 - Switzerland on Friday said it was banning chicken imports from Britain and the Netherlands, as Dutch officials said they detected bird flu on three more farms.

The Swiss move will come into effect on Saturday and apply to live chickens and chicks as well as eggs from the affected zones in the two countries, the Federal Office for Food Security and Veterinary Affairs said.

Belgium meanwhile ordered poultry owners to confine their birds as a precautionary measure following the outbreak in neighbouring Holland.

The Dutch economic affairs ministry confirmed that a second bird flu outbreak detected on Thursday on a farm at Ter Aar, close to the first case east of The Hague, was the highly pathogenic H5N8 strain, previously detected only in Asia.

Some strains of avian influenza are fatal for chickens, and pose a health threat to humans, who can fall sick after handling infected poultry.

Bird flu was detected on three other farms in and around Kamperveen, about 100 kilometres (60 miles) north of the first outbreaks, the Dutch economic affairs ministry said in a statement on Friday.

The birds on all three farms will be destroyed and the farms disinfected, the ministry said, with tests being carried out to establish if the strain is the highly infectious H5N8 strain.

Britain has also reported an avian influenza outbreak at a duck breeding farm in Yorkshire, northern England, which on Tuesday was confirmed to be H5N8.

The H5N1 strain of bird flu has killed more than 400 people, mainly in southeast Asia, since first appearing in 2003.

Another strain of bird flu, H7N9, has claimed more than 170 lives since emerging in 2013.

The H7N7 strain of avian flu severely hit the Netherlands in 2003 with health authorities destroying some 30 million birds in an effort to quash an outbreak.

There are some 95 million chickens on Dutch poultry farms and egg exports totalled some 10.6 billion euros ($13.2 billion) in 2011, according to the latest Dutch statistics.