Farmers are being warned to take emergency precautions to curb an outbreak of the deadly foot and mouth disease.

A suspected outbreak of the disease at an Essex abattoir has been traced to a farm in Buckinghamshire, around which a five-mile animal movement exclusion zone has been set up.

The zone includes Steeple Claydon, near Bicester, and farmers across Oxfordshire have been told to take extra precautions.

Foot and mouth affects only animals with cloven hooves and is spread rapidly by contact between animals, transmission via people or transport or by air.

There is no risk to humans, pets or the food chain, but David Orpwood, the chairman of the National Farmers' Union in Oxfordshire, Berkshire and Buckinghamshire, warned that the disease was lethal to some animals.

He said: "It is a highly virulent disease which spreads like wildfire. Animals get lesions in their mouth, on their tongue, on their legs and on their hooves, then they die.

"If any farmer should see any abnormality frothing at the mouth or lesions especially then they should call a vet immediately."

A temporary ban has been imposed on exports of livestock, meat and dairy products from Britain.

Anybody with questions about the outbreak should contact the National Farmers' Union on 01730 408 000.