Authorities tested slaughtered cattle for a suspected new case of foot-and-mouth disease.
Britain's environment department said the animals were showing clinical signs of the disease, which has struck cattle and sheep on farms close to a medical research laboratory.
The latest suspected case is inside a 3-kilometer (1.9-mile) protection zone set up close to the latest reported cases in Surrey, south of London, the Department for Environment, Food and Rural Affairs said.
"The decision has been taken to slaughter cattle on suspicion of foot-and-mouth disease on a farm in Surrey," a spokeswoman said on condition of anonymity in line with department practice.
Two new cases were detected in Surrey last week and government vets confirmed the disease was the same strain found at three other locations where a foot-and-mouth outbreak began Aug. 3.
That outbreak was centered near the government-funded Institute for Animal Health, a diagnostic laboratory, and Merial Animal Health, a British unit of the U.S.-French pharmaceutical firm Merial Ltd.