A British Airways London-bound flight has been grounded in Montreal after a 'suspected device' onboard the plane raised bomb alarm.

A Sky News report noted that the alert was raised after a suspicious device was found on-board the plane. The reported also noted that the passengers were searched after they embarked from the plane. 

Bomb squads along with sniffer dogs are checking the luggage-hold of the Boeing 747 British Airways flight that made an emergency landing in Montréal–Pierre Elliott Trudeau International Airport at 6 am ET following a bomb threat.

Montreal Gazette reported that the Canadian police was alerted of a possible bomb situation around 5.15 am, forty-five minutes before the plane landed at the airport.

BA274 was on its way to London from Las Vegas. There were 312 passengers on-board the London-bound flight and all of them have been evacuated, reports said.

Images shared on social media show passengers being taken away from the plane to the waiting area of the airport.

The plane left McCarran International around 9.30 PM Pacific Time and was to land at Heathrow at 3.25 pm BST, according to CBC.

British Airways said on Twitter that "the Captain took the decision to divert the aircraft as a precaution."

"The safety and security of our customers, crew and aircraft are our highest priorities at all times. We are looking after the customers and will provide hotel rooms for them and will rebook them to other flights as soon as we can."