Trio guilty of transatlantic bomb plot

Ringleader Abdulla Ahmed Ali was found guilty of conspiring to murder thousands in the plot, whose discovery triggered wide-ranging new rules on carrying liquids on commercial aircraft.

Tanvir Hussain, 28, and Assad Sarwar, 29, were found guilty on the same charges of plotting to carry out bombings on aircraft flying from London's Heathrow airport to the United States and Canada.

The three men were previously found guilty of conspiracy to murder, but the jury in their first trial could not decide on charges that they had plotted to kill people by bringing down airliners.

Home Secretary Alan Johnson hailed the verdicts, saying: "I am pleased that the jury has recognised that there was a plot to bomb transatlantic flights and that three people have been convicted of that plot.

"This case reaffirms that we face a real and serious threat from terrorism.

"This was a particularly complex and daring plot which would have led to a terrible attack resulting in major loss of life."

Bomber's flat bugged

The counter-terrorism operation to prevent the plot was the biggest ever in Britain.

"I cannot thank enough those involved for their professionalism and dedication in thwarting this attack and saving thousands of lives," he said.

Woolwich Crown Court heard that plans for the attack were drawn up in Pakistan and passed on to Ali. He returned to Britain to assemble a terror cell, gather material and identify targets.

However, he was under surveillance by British security forces at the time.

Undercover officers bugged his flat in east London, where he met others to build the bombs, as part of a police investigation that cost a total of STG35 million ($A67.3 million).

The plan was to smuggle home-made bombs made of hydrogen peroxide onto the planes in soft drink bottles. Refilled batteries would carry the chemical detonator, with the bombs set off using a charge from a light bulb filament.

Mid-air assembly, detonation

They would have been assembled and detonated in mid-air by a team of suicide bombers, causing untold damage.

Police believe the design was thought up by a mystery bombmaker with links to the al-Qaeda terrorist network. He has never been identified.

Ali, who was born in Britain, was inspired by suicide bombers who attacked London's transport system on July 7, 2005, killing 52 people as well as the four bombers, prosecutors said.

He is thought to have finalised the plans during a six-month trip to Pakistan in 2005, and intended to teach non-Muslims "a lesson that they will never forget".

Ali threatened further attacks against the West in a suicide video recorded in his flat, warning the British public to expect "floods of martyr operations" that would leave body parts scattered in the streets.

Plot 'an elaborate publicity stunt'

In their defence, Ali, Sarwar and Hussain had argued that the plot was an elaborate publicity stunt designed to call attention to an internet documentary attacking British foreign policy.

The jury rejected this, and the men will be sentenced on Monday, September 14.

However, they found Ibrahim Savant, 28, Arafat Waheed Khan, 27, and Waheed Zaman, 24, not guilty of the airline plot.

Donald Stewart-Whyte, 23, was found not guilty of both conspiracy to murder on aircraft and conspiracy to murder.

After 54 hours of deliberations, the jurors failed to reach a verdict on the role of Umar Islam, 31, in the plot, although he was convicted of the second charge of conspiracy to murder.