Tests on cattle culled in southern England confirmed a second foot-and-mouth disease outbreak, Environment Secretary Hilary Benn said Tuesday, raising fears that the virus could spread.
Tests had been carried out on around 50 cattle late Monday, Benn said.
The cows were within the initial two-mile-radius protection zone set up Friday around a farm 30 miles southwest of London where a first group of infected cattle was found.
Authorities on Monday night had begun slaughtering the group of cattle suspected of being infected, Britain's Chief Veterinary Officer Debby Reynolds said. About 120 cows were destroyed on a nearby farm after the virus was first detected last week.
The investigation into the source of the disease is focusing on a research laboratory near the Surrey farm where two cattle were discovered with the disease last week. The strain of the disease found in the infected cattle is the same one used at the laboratory.
The laboratory is shared by the government's Institute for Animal Health, or IAH, and a private pharmaceutical company, Merial Animal Health -- the British arm of Duluth, Ga.-based Meria.
Merial said Monday it found no evidence of a breach in biosecurity, and the IAH claimed a check of records found "limited use" of the virus in the past four weeks.
Prime Minister Gordon Brown, who came back early from vacation to handle the government's response to the outbreak, held talks at his London office with farming union leaders and pledged to do everything possible to avoid a repeat of mass infections that devastated the economy in 2001.