Washington, Oct 20 (DPA) The US has detected the first case of swine flu in pigs, the Department of Agriculture said Monday.
The virus was found in a sample taken from a state fair in Minnesota. More samples were being tested, but the department said it was unlikely to spread because fair pigs are typically kept separately from large-scale commercial pig farms.

Agriculture Secretary Tom Vilsack stressed that humans could not contract swine flu through pork products and urged other countries not to restrict US imports because of the discovery.

More than 4,000 people around the world have died from swine flu, known scientifically as H1N1 influenza, which originated in Mexico and quickly spread to the US.

Swine flu has badly affected pork producers in the US and Mexico, though the virus is actually a mix of strains from pigs, humans and avian influenza.

Several countries, including Russia and China, restricted pork imports from the US and Mexico at the start of the swine flu outbreak in April, despite assurances from the World Health Organisation that the virus could not be contracted by eating meat.

Most countries have since lifted the import bans. But China, the largest market for pork products, remains closed.