A Korean Airlines Boeing 777 travelling from Vancouver to Seoul diverted to a Canadian Forces base on Vancouver Island after the airline received a call about a threat on board.
Korean Air said 25 minutes after take-off from Vancouver International Airport its US call centre received the threat and decided to turn the aircraft around.
In Washington, a US official said that two US F-15 fighter jets were scrambled.
The Canadian Forces said the flight was travelling from Vancouver International Airport and was diverted to Comex air base, 70 miles outside Vancouver, at about 5.30pm yesterday.
The Canadian Broadcasting Corporation reported that the plane was diverted after a bomb threat was made in a telephone call to the airline's Los Angeles office. According to the CBC report, the flight was escorted by US Air Force fighter jets that had been scrambled from Portland, Oregon.
A Korean Air spokesman said he was aware of the incident but declined to comment on the reported bomb threat.
Vancouver International Airport spokeswoman Alisa Gloag said flight 72 with 149 passengers landed safely at Comox about three hours after it took off.
The military said emergency teams were securing the aircraft in accordance with normal procedures.
The military base is on the east coast of Vancouver Island.