Canary Wharf: more smoke and mirrors?

In the same week that the US claimed to have smashed a plot to blow up its tallest building, an alleged threat to the Canary Wharf tower, which holds that title in Britain, returned to prominence.

According to an internal report by the US Department for Homeland Security, obtained by ABC television, US intelligence services thwarted an al-Qa'ida plot three years ago to hijack a plane at Heathrow and fly it into Canada Tower in Canary Wharf, east London. The report, an assessment of aviation security written earlier this month, said: "Al-Qa'ida planned to hijack flights departing London's Heathrow airport and crash them into the airport and a skyscraper in the Canary Wharf financial district."

This was said to be one of a series of "spectaculars" planned by the terrorists. According to ABC, the plot involved using converted camera flashes to seize control of the jets, with other targets in the US, Australia and Italy.

Though the plot was said to have been uncovered in the summer of 2003, little more is known. The claim echoes reports in November 2004 by ITN and the Daily Mail, which alleged that Western intelligence agencies had thwarted a plot to fly hijacked planes into Canada Tower the previous year. There was said to be a similar threat to Heathrow - a claim which seemed to justify the decision in February 2003 to deploy tanks at the airport.

But the British reports, thought to have been based on one Cabinet source, were rebutted by ministers, and the Home Office and Downing Street denied any leak. Peter Hain, then Leader of the Commons, was emphatic: "If there was a specific threat to Canary Wharf ... we would have said so... and that leak, if it was a leak, did not come from a government minister or, as far as I know, a government source."

The question now is whether the latest US disclosures corroborate those claims from 2004 or whether, like many other alleged terror plots, they are little more than theoretical scenarios, rumours or mistranslations. The latest claims appear to be based on the same source: computer files belonging to an aide to Osama bin Laden called Mohammed Naeem Noor Khan, which were seized in Pakistan in 2002. But that information, said to include diagrams and maps, was four years old even then.