Restrictions brought in to deal with the outbreak of bird flu at a Bernard Matthews farm will have to stay in place for at least another three weeks, it emerged yesterday.

Restrictions brought in to deal with the outbreak of bird flu at a Bernard Matthews farm will have to stay in place for at least another three weeks, it emerged yesterday.

The announcement by environment secretary David Miliband is bad news for free-range poultry keepers, who are having to keep their birds inside if they live near the affected farm in Holton.

And across a 2,000 sq km area, running up to the A47 near Norwich and across to the A140, poultry must be kept apart from wild birds, there can be no bird gatherings or sales, and birds cannot be moved without a licence.

The decision was met with anger from poultry keepers who had hoped the restrictions would be lifted this Saturday at the end of the minimum three-week period.

There has been no sign that the virulent H5N1 virus has spread outside the Bernard Matthews farm which until this month was home to 160,000 turkeys.

Virginia Storey, who keeps free- range chickens within half a mile of the factory, said: "It is outrageous. Everyone I have spoken to who keeps poultry feels the same. It is very upsetting to have to keep your healthy birds inside.

"They should be worrying less about that and more about the biosecurity at Bernard Matthews and the gulls and the rodents that have been getting in."

In a statement to the House of Commons yesterday, Mr Miliband said transport from Hungary and biosecurity in Holton were the focus of the continuing investigation into the cause of the outbreak.

"Infection could have entered the turkey sheds carried from waste products by birds or rodents or on footwear and clothing," he said, adding: "I am assured that waste products on the site are currently being dealt with in a satisfactory way."

And he warned: "The expert advice available to me is that there is a constant low risk of bird flu to the UK, and higher risk during mig-ration seasons. There can be no guar-antee against further outbreaks."

It also emerged that no wild birds had been caught and tested for bird flu in Suffolk, although seagulls living on the Holton factory site have had their droppings tested and found to be negative. It is possible for wild birds to carry the disease without falling victim to it, and a government report found large numbers of gulls living on the site and feeding on meat waste left in open bins.

Despite appeals to the public to report dead birds, and extra moni-toring in the area, just 12 dead birds have been tested. All were found to be free of the virus. The nearest testing of live birds has been carried out at Welney in west Norfolk.

Meanwhile, Caroline Lucas, the eastern region's Green party MEP, has demanded that the European Commission investigate the decision to allow poultry processing to resume at the factory in Holton.

She said: "If the government doesn't follow EU rules, it is British farmers who will pay the price, as this failure means the disease is more likely to strike again - and the EU will be able to blame the UK government and deny any compensation claims.

"I have today demanded the European Commission investigate the government's decision to allow the plant to reopen so soon."