Britain's longest terrorist investigation ended yesterday when three Muslims were convicted of conspiring to become suicide bombers in a plot to blow up transatlantic airliners.

Ibrahim Savant, Arafat Waheed Khan, and Waheed Zaman made vitriolic suicide videos in which they blamed the West for their actions.

They were seen meeting the central figures of the plot and entering the bomb factory in Walthamstow, east London, during a six-week surveillance operation by police and MI5.

Described by Peter Wright, QC, prosecuting, as the "frontline troops" in "a deadly and co-ordinated campaign against the general public", they had claimed they were persuaded to make the videos as part of a protest film by the leader of the plot, Abdulla Ahmed Ali, an old school friend of two of them.

The verdicts bring to 11 the number convicted as a result of the investigation. The attacks would have been worse than those of September 11 and could have killed 10,000 people.

Abdulla Ahmed Ali researched seven flights from Heathrow to six cities in the United States and Canada.

But police believe the men were considering an even larger attack after they were bugged discussing as many as 18 suicide bombers.