Britain banned the export of livestock and livestock products Saturday after foot-and-mouth disease was discovered on an English farm, and authorities halted the movement of cloven-hoofed animals nationwide in a bid to control the highly infectious virus that devastated the farming industry six years ago. Prime Minister Gordon Brown said officials vowed to work night and day to halt the spread of a disease that led to the slaughter of 7 million livestock and badly damaged the agriculture industry and rural tourism in 2001. The government of the time was heavily criticized for being slow to act, giving the disease a chance to spread. "Our first priority has been to act quickly and decisively," said Brown, who returned to London from a summer holiday to deal with the outbreak. He chaired a meeting of the government's crisis committee, COBRA, on Saturday. "I can assure people ... we are doing everything in our power to look at the scientific evidence and to get to the bottom of what has happened and then to eradicate this disease." Department for Environment, Food and Rural Affairs, or DEFRA, said Britain had banned the export of all animals with cloven hooves, including cows, sheep and pigs. The ban covers live animals, carcasses, meat and milk. The United States and Japan banned British pigs and pork products. British beef is already banned in both countries because of mad-cow disease. The US Department of Agriculture said that it was barring all products derived from foot and mouth-susceptible species in Britain. DEFRA said animals on a farm near Wanborough, about 50 kilometers (30 miles) southwest of London, had tested positive for the disease, which affects cloven-hoofed animals including cows, sheep, and pigs and goats. It does not affect humans. The case is the first in Britain since 2001, when the carcasses of livestock were burned on huge pyres that dotted the country, and large swaths of countryside were declared off-limits to visitors, damaging tourism. DEFRA did not immediately say how many animals were infected, but said all livestock on the farm would be slaughtered and incinerated. Officials stressed there was no plan to burn the carcasses on pyres - a sight that horrified many Britons in 2001. Brown said officials were "doing everything in our power to avoid a repeat" of the scenes of six years ago. At the infected farm, veterinary workers in protective white coveralls rounded up cattle and put them into pens. Vehicles entering and leaving the farm were sprayed with disinfectant. Authorities imposed a 3-kilometer (2-mile) radius protection zone and a surveillance zone of 10 kilometers (6 miles) around the farm. DEFRA said a ban was also imposed nationwide on moving all cloven-hoofed animals, including pigs. Scientists were carrying out tests to determine the strain of the disease, and whether vaccination would be possible to halt its spread. The government's chief veterinarian, Debby Reynolds, said it was too soon to guess how the disease had got to Britain - whether through the illegal movement of animals, on the wind or by accidental contamination - and how far it might spread. "It's important not to rule out any possible source in our inquiries," Reynolds said. "The objective is to eradicate foot and mouth disease. It is a big blow for it to be back in UK territory." She encouraged farmers to look for signs of illness in their livestock, and said there had been a "small number" of reports from other farms. None had so far proved to be foot-and-mouth. The government was criticized for not using vaccines in the 2001 epidemic. A report on the epidemic by a senior scientific body, the Royal Society, concluded that vaccination should be a major tool of first resort in the event of future outbreaks. Farmers near the infected site were worried, but hopeful that quick action would contain the disease. "We are keeping our fingers crossed but there is really nothing we can do about it except wait," said Michael More-Molyneux, whose farm is about 8 kilometers (5 miles) from the infected site. The 2001 outbreak started with a pig herd in northern England and spread to cows and sheep. It eventually infected more than 2,000 farms and shut Britain out of the world's livestock export markets. British taxpayers paid more than US$2 billion for compensation, disinfecting, veterinarians and the slaughter. The total cost to the country was estimated at 8 billion pounds (US16 billion; â‚¬12 billion at current values). It was almost a year before Britain was declared free of the disease, and months more before British exports were allowed to resume. Tim Bonner, spokesman for the Countryside Alliance, said farmers were extremely worried by the latest outbreak. "Farmers around the country will be hoping and praying that this is an isolated incident and that the disease is not already widespread, because last time when we found out about it, it was already everywhere," he said. "We hope and pray that the lessons from last time have been learned."