Photo: Contributed

WestJet says a bomb threat it believes was a hoax prompted the airline to divert a Vancouver-to-Toronto flight to Calgary on Wednesday night.

WestJet says flight WS722 landed safely and the 30 passengers and five crew members on board exited the aircraft via stairs.

The airline says it diverted the Boeing 737-700 after receiving the threat "out of an abundance of caution."

This was the fourth time a WestJet flight has been the subject of a threat in the last five days and the fifth such incident involving a Canadian airliner in a week.

On Tuesday, a WestJet flight with 113 passengers and five crew members landed on a flight from Toronto to Saskatoon landed at Saskatoon following a threat but police say a search of the aircraft found no bomb.

A WestJet flight en route from Edmonton to Toronto was forced to divert to Winnipeg on Monday night because of an unspecified threat, passengers had to jump down evacuation slides and six people sustained minor injuries.

Last Saturday morning, a WestJet flight from Edmonton to Halifax landed in Saskatoon after police said a call had been made claiming an explosive device was on board.

And last Thursday, St. John's International Airport was temporarily closed because a note was found in the washroom of an Air Canada flight that authorities considered a potential bomb threat.

In all of the cases, searches of the aircraft unearthed nothing suspicious.

Police say the investigation is continuing and there have been no arrests.