The British government has ordered the slaughter of some 35,000 chickens at a farm in the south-eastern county of Norfolk after dead birds tested positive for a strain of bird flu, it was reported Thursday.
Early tests showed it was likely to be the H7 strain, virulent among chickens but less of a risk to humans than the H5N1 variant, which can be fatal.
Last month a swan in Cellardyke, Scotland, tested positive for H5N1 - the only confirmed case in the UK so far.
An outbreak of H7N7 in the Netherlands led the Dutch government to order the slaughter of more than 30 million birds in 2003.
Britain's ministry for environment, food and rural affairs (Defra) said the measure was "precautionary".