Laboratory results on dead chickens from an Oxfordshire farm show the H7 strain of bird flu is highly contagious.

Further tests will now take place now to try to establish the exact strain and links with previously identified Avian flu viruses.

Up to 25,000 laying hens at Eastwood Farm, between Shenington and Shutford, about 10 miles west of Banbury, will be slaughtered today in a bid to stop the disease spreading.

A detailed epidemiological investigation is also under way to try to establish the origin of the disease.

A 3km protection zone around the farm and a 10km surveillance zone remain in place.

The movement of birds and bird products have been banned in the whole of the temporary zone and restrictions have been imposed on people housing or having contact with wild birds. All bird gatherings have been banned.

Defra is urgently considering whether any wider measures may be needed.

The Health Protection Agency has confirmed that the risk to public health remains low.

The Food Standards Agency has also confirmed that there are no safety implications for the human food chain.

Poultry keepers are urged to be extremely vigilant, practice the highest levels of biosecurity and report any suspicions of disease to their local Animal Health Office immediately.