Two more cases of foot-and-mouth disease are feared

Fears that foot-and-mouth could have spread as far as Kent were raised last night after the chief veterinary officer, Debby Reynolds, imposed control zones around two more areas.

A cordon was thrown around Honeychild Manor Farm on Romney Marsh in Kent, 80 miles from the original outbreak in Surrey. A second new control zone is based on Chessington World of Adventures theme park, also in Surrey.

The theme park incorporates Chessington Zoo, where a sheep was taken ill yesterday. A Chessington spokeswoman said the zoo had alerted the environment department (Defra) as "standard procedure" but added: "There is no foot-and-mouth at Chessington." Calling in Defra was "purely a precautionary measure to ensure the well-being of the animals and protect the local community. There is no reason to suspect that anything but a full clearance will be received."

After daily health checks on the zoo's animals, a vet had been called to examine a sheep. "Because of the high state of alert currently in place due to the recent cases of foot-and-mouth disease, it was decided to immediately check all our cloven hoof stock for any signs of disease and do necessary tests; and as part of our standard precautionary procedures Defra was also alerted.''

She said the Children's Zoo and Creature Features areas of the park would remain closed to the public.

A Defra spokesman said: "A temporary control zone has been set up in Surrey; we cannot confirm anything more than that at present."

As tests were carried out on animals showing symptoms of the disease, Hilary Benn, the Environment Secretary, said the reports of possible outbreaks by alert farmers proved that the system was working.

Confirmation that the disease has spread to Kent would be devastating to the Government. Before yesterday's alert, the Prime Minister and officials were increasingly confident that the outbreak had been contained.

Kent police were stationed at the entrance to Honeychild Manor Farm yesterday to prevent entry. A large tractor was parked across the entrance and buckets of disinfectant were put out. In the yard, workers were spraying cars.

The farm, which has a herd of 250 dairy cows, was cordoned off after the farmer, Stephen Furnival, reported illness among his cattle. Veterinary staff who examined three animals could not be sure what was causing the symptoms, Defra said. Officials were awaiting results of tests last night.

Dr Reynolds said: "The containment and eradication of foot-and-mouth disease remains our priority. This is why we have moved swiftly to put in place a temporary control zone while we investigate this development in Kent. At this stage disease has not been confirmed." She added: "I would take this opportunity to reiterate the need for the highest standards of biosecurity on farms, and for people to remain vigilant for disease."

The Prime Minister cancelled a holiday in Dorset to take personal charge of the emergency measures after the outbreak was confirmed on a farm near animal health laboratories at Pirbright, Surrey, on 3 August. He ordered an independent inquiry by Professor Brian Spratt, which is expected to be delivered this week.

The Health and Safety Executive (HSE) also conducted an investigation into the likely source of the outbreak at the two laboratories at Pirbright, one run by the Institute for Animal Health and a vaccination plant operated by the US-based Merial company. Soil samples were taken from around a manhole cover which may have flooded in the Merial site.

Suspicions were raised that the outbreak was caused by a leak from Merial when vaccines were made in mid-July. The HSE has so far been unable to pinpoint which lab was responsible. Both used the strain of the disease found on the farm, which has not circulated in Britain since 1967.