Japan suspended beef exports Tuesday after detecting suspected cases of foot-and-mouth disease in several cows in the south of the country, officials said.

Three of 16 beef cows raised at a farm in Miyazaki developed mouth ulcers - a typical early symptom of the disease - earlier this month, prompting authorities to impose a ban that will last at least three months, said Agriculture Minister Hirotaka Akamatsu.

Japan exported 565 tons of beef, worth $40 million (3.8 billion yen) in fiscal 2009 ended March, mostly to Vietnam, Hong Kong and the U.S., according to the ministry.

Virus samples tested positive in an initial examination, ministry official Keiji Fushimi said, adding that results of more detailed tests are pending.

If confirmed, the infection is Japan's first since 2000, when an outbreak hit Miyazaki - a southern prefecture known for its prized beef - and northern Hokkaido.

All 16 cows at the farm will be dest royed and shipment and transport of cattle and pigs in the area are restricted, affecting 27,000 cows and 183,000 pigs.

South Korea has slaughtered thousands of cows since January, the country's first outbreak of the disease in eight years.

The disease is often fatal for cloven-hoofed animals including cows, sheep, pigs and goats, causing blisters on the mouth and feet. It does not affect humans.

Copyright 2010 The Associated Press.