A strain of bird flu discovered on a poultry farm in British Columbia's Fraser Valley is not the same type that has been blamed for killing at least 65 people in Asia since 2003, the Canadian Food Inspection Agency confirmed on Sunday.

The H5 virus found in a commercial duck on the Chilliwack farm is a low pathogenic North American strain, CFIA veterinarian Cornelius Kiley told reporters.

A sign posted at the farm in Chilliwack

Despite news that the virus can cause only mild disease in birds, a CFIA-ordered cull of birds on the farm will proceed.

Kiley said while there's no immediate risk to domestic birds, there are concerns the virus could mutate.

About 65,000 birds will be killed at the facility, one of the farms affected in a cull carried out in the spring of 2004 in the Fraser Valley and Lower Mainland. Millions of chickens were killed in an effort to stop the spread of the avian flu.

On Saturday, CFIA said two wild ducks in Manitoba have tested positive for H5N1 viruses, but not the dangerous strain that has spread from birds to people in Southeast Asia.

Officials called the viruses "low pathogenic," meaning they're not viewed as a public health threat.

"I want to emphasize that the H5N1 subtype detected in Manitoba is completely distinct from the strain currently present in Asia," Brian Evans told a news conference.

"From a genetic perspective, there are significant strain differences in their structure," said Evans, the agency's chief veterinary officer.

The viruses were isolated as part of a cross-country surveillance program to find what avian flu viruses are being carried by wild ducks in Canada.

Agency officials said they have also isolated an H5N3 subtype in two birds from Quebec.