A strain of H5 bird flu virus has been found in a commercial farm duck in the Fraser Valley of Canada's western province of British Columbia, officials said on Friday.

The Canadian Food Inspection Agency (CFIA) is visiting farms ina 5 km radius around the infected premises to test birds and is warning bird owners to practise strict biosecurity, the CTV television reported.

The provincial officials said they are not sure which strain ofthe H5 virus was found in the duck. They stressed there is no risk to human health, but the farm where the duck was found has been quarantined.

"Due to the precautionary principle, it's really important to lock down as quickly as possible and make sure we quarantine before it spreads further," said Dr. Eric Young, Deputy Medical Health Officer of the British Columbia.

Swab samples from the duck are on their way for further testing and results could take up to 48 hours. Dr. Jim Clark, with the CFIA, said he was not surprised by the finding.

"I think it was something we could anticipate was going to happen in the domestic waterfowl population," he told CTV. "We know that waterfowl are the natural reservoirs of all the avian influenzas.

It was something that could have been anticipated, however now that we've made the discovery and we're going to have to deal with that situation, " Clark said.

Wild ducks in various locations across Canada have carried the H5 virus, including Quebec and Manitoba. The duck found in British Columbia may have had contact with wild ducks that carried the H5 virus, he said.

In 2004, an outbreak of avian flu eventually hit farms in a 70-km-wide swath from the Vancouver's eastern suburbs to Chilliwack in the eastern Fraser Valley, forcing the slaughter of 17 million birds. In the end, about three million birds were foundto be diseased and the rest were allowed to be sold to consumers.