A strain of H5 bird flu virus was detected in a second commercial poultry operation in southern British Columbia, close to where the first avian influenza case was discovered less than a month.

About 12,000 birds on the Fraser Valley farm will be destroyed by Thursday, the Canadian Food Inspection Agency said Wednesday.

The flock was tested as part of surveillance activities in a three-kilometre radius around E&H Farms, the commercial turkey farm where low-pathogenic H5 N2 avian influenza was detected on Jan. 24, the agency said in a news release.

Tests indicate that the strain of bird flu at the new premises is also low pathogenic and similar to the original strain identified on E&H Farms. Further testing is underway to confirm the precise subtype and strain of the virus.

"The type of the virus at this time does appear to be fairly closely related to the H5 N2 that was identified on the first premises," Sandra Stephens, a disease control specialist with the CFIA, told CBC News in an interview.

But she said she doesn't believe the birds in the first farm infected those in the second one, which her agency has not named.

"This premises is toward the outer limit of that initial three-kilometre radius that was drawn around the index premises," she said.

The CFIA has drawn a new three-kilometre surveillance radius around the second farm, overlapping some areas of the three-kilometre radius around E&H Farms.

The CFIA placed quarantines on an additional 10 premises. Three of the 36 farms under quarantine after the E&H detection have completed a 21-day monitoring period and met the requirements for quarantine release.