Britain has found bird flu in a dead swan in Scotland, the government said on Wednesday.

Preliminary tests have confirmed a case of the H5 strain of the virus, the Department for Environment Food and Rural Affairs said in a statement.

More tests for the deadly H5N1 strain are under way and the results should be announced on Thursday.

"We are already in a high state of readiness," Britain's Chief Veterinary Officer Debby Reynolds said in a statement.

She has canceled a national bird flu exercise which began this week to test the country's response to any outbreak.

"I brought to an end the national avian influenza exercise to ensure that we can bring all our resources to bear on this situation."

Officials have set up a 3 km (1.8 mile) protection zone in Fife, eastern Scotland.

Bird flu remains essentially an animal disease, but can infect people who come into direct contact with infected birds.

It has killed 108 people since late 2003, according to the most recent figures from the World Health Organization.