Testing found the virus at a turkey farm in Abbotsford and a broiler chicken breeding facility in Chilliwack, officials said in a statement released just after noon on Tuesday.
"The Canadian Food Inspection Agency (CFIA) has placed the two farms under quarantine to control disease spread and the industry sector has been notified to adopt enhanced biosecurity practices," said the statement.
Testing was conducted on Monday after large numbers of birds died at the farms over the weekend.
"Further testing by the CFIA is underway to confirm pathogenicity and to determine the precise subtype and strain of the virus," CFIA said.
Pathogenicity refers to the severity of the illness caused in birds, said officials. The results are expected within days, but officials say the virus has caused heavy mortality among the infected birds.
The remaining birds on the farms will be killed and disposed of under CFIA supervision, and the farms will remain under quarantine until the barns, equipment and vehicles are disinfected.
Officials note the virus does not pose risks to food products that are properly cooked and rarely affects humans who do not have direct contact with infected birds.
4th outbreak since 2005
The outbreak is the fourth in the Fraser Valley since 2004
In 2009, an outbreak of avian flu in the same region led to the quarantine of several farms
In another Fraser Valley outbreak in November 2005, two duck farms were infected with the H5N2 strain of the virus.
In 2004, an H7-type flu transformed into a highly contagious strain. Farm after farm was quarantined until finally about 15 million birds — almost the entire valley poultry population — were destroyed.