Two more Fraser Valley poultry farms have been placed under quarantine as a precaution to contain the spread of avian flu, said Canadian Food Inspection Agency officials Wednesday.

The newly quarantined farms are located in Abbotsford and Chilliwack between two farms where avian flu was announced Tuesday. All the birds at both farms will be destroyed, and the farmers will be compensated.

Dr. Harpreet Kochhar, Chief Veterinary Officer of Canada, said avian flu has not yet been detected at the new farms

"Sampling and testing is underway for these additional premises," he said.

"As avian influenza is highly contagious and can spread rapidly, it is possible that additional at-risk farms may be identified in the coming days."

Avian flu chicken AP

An H5 influenza outbreak in B.C.'s Fraser Valley has led to the quarantine of four farms and the deaths of thousands of chickens and turkeys. (Associated Press)

The avian flu outbreak killed more than 6,000 turkeys and chickens at the first two farms on the weekend. Another 12,000 birds at those facilities are being euthanized to contain the outbreak.

The B.C. Poultry Association has said it's confident biosecurity measures will be able to stop the spread of avian flu in the region.

No human has become ill from H5 influenza outbreak, according to public health officials.

The virus does not pose a risk to food products that are properly cooked.

World markets react to B.C. avian flu outbreak

Meanwhile, the avian flu outbreak has led to trade restrictions in several Asian markets, according to Agriculture Canada.

Japan has imposed trade restrictions on all Canadian poultry products, and chicks from B.C..

South Korea has banned imports of Canadian chicks, and Taiwan has put trade restrictions on B.C. poultry and poultry products, said Agriculture Canada in an emailed statement.

Hong Kong's ban covers any poultry meat or products from the Fraser Valley Regional District "for the protection of Hong Kong's public health," according to a statement from the government of Hong Kong's Food and Environmental Hygiene Department.

Hong Kong imported 7,000 tonnes of frozen poultry and about 170,000 poultry eggs from Canada between January and October of this year, said the statement.

Hong Kong has had its own problems with avian flu, including an H5N1 outbreak in 2011 that lead to the slaughter of more than 19,000 birds and a ban on the sale of live poultry for three weeks.

With files from Dan Burritt