Plot to crash plane into Canary Wharf

Under threat: The tallest Canary Wharf skyscraper is the tallest skyscraper in Europe, until more even taller buildings are built in London

Al Qaida was planning to hijack aircraft and crash planes into Heathrow airport and London's Canary Wharf, according to a US security report.

The British landmarks were among a number of targets around the world being considered by terrorist operatives.

In one plot, the terrorists were going to use cameras and their flash attachments to conceal bombs and stun guns as part of an "ingenious" plot. Using the converted weapons, it is thought it would have been possible to access the cockpit and even bring down the plane.

These weapons were to be used against targets on the east coast of the US, the UK, Italy and Australia, but were thwarted in 2003, according to the report.

In the same year, Prime Minister Tony Blair was criticised for deploying the armed forces to Heathrow.

A separate plan to fly a plane into a skyscraper in east London's Canary Wharf was brought to light in 2004.

Details of the al Qaida plots were revealed in a report by the US Department of Homeland Security, obtained by the US television channel ABC News.

It said a total of nine hijack plots since September 2001 had been uncovered "demonstrating a continued commitment to attack aviation-related targets".

A Homeland Security official was quoted as saying: "Al Qaida planned to hijack flights departing London's Heathrow Airport and crash them into the airport and a skyscraper in the Canary Wharf financial district of London."

The official went on to describe al Qaida as adapting "to increased aviation security by shifting planned suicide hijackings from domestic carriers to international flights... to take advantage of perceived less effective security screening at some foreign airports".