Investigations are underway by DEFRA to establish how turkeys on a farm in Suffolk came to be infected with the H5N1 strain of avian flu.

In response to the incident, farmers across the country have also been urged to step up their vigilance and make sure they are exercising good biosecurity arrangements.

A cull of 160,000 birds on a Bernard Matthews farm near Halesworth is expected to come to a halt later on Monday (5 February).

The birds have been gassed and their carcasses are being transported to Staffordshire for disposal.

DEFRA has announced that a protection zone of three kilometres radius and a surveillance zone of 10 kilometres have been established around the premises (clink link for map).

Movement restrictions have also been imposed and poultry must be isolated from wild birds.

A wider restricted zone has also been imposed, covering east Suffolk and South East Norfolk bounded to the west and the north by the A140 and A47 respectively, an area of approximately 2090sqkm.

It requires the isolation of poultry from wild birds, and requires movements to be licensed.

All bird gatherings - including shows, markets and fairs, and pigeon races - have been banned nationwide.

The Food Standards Agency has issued clear advice that avian flu does not pose a food safety risk for UK consumers.

It has stressed that even if present in meat or eggs the virus will be killed by cooking or by saliva and gastric acid when consumed.

Visit to keep up with DEFRA's latest on the avian flu outbreak.