Three Britons were convicted on Thursday of plotting to murder hundreds of people in suicide bombings after being recruited by an al Qaeda-inspired cell bent on blowing up transatlantic airliners bound for North America.

The three men, who recorded martyrdom videos threatening waves of attacks against Britain and the United States, worked with the gang that planned to bring down planes with home-made liquid bombs.

Their conviction follows one of Britain's biggest counter-terrorism investigations and a series of trials around a plot that prosecutors said could have been on the same scale as the 9/11 attacks.

Twelve people have now been convicted in connection with the plot that led to extra security checks at airports worldwide and tight restrictions on passengers carrying liquids onto planes.

The three convicted on Thursday had faced two previous trials in 2008 and 2009. A jury at their first trial failed to agree a verdict. They were acquitted at the second trial of knowing that the plot was targeting planes.

Prosecutors made the unusual decision to push for a third trial where the three faced a broader charge of conspiracy to murder, replacing the previous charge of plotting to kill people on airliners.

Ibrahim Savant, Arafat Waheed Khan and Waheed Zaman were convicted by a jury at Woolwich Crown Court, east London, and will be sentenced on Friday, the Press Association reported. They face a maximum sentence of life imprisonment.

'MID-AIR EXPLOSIONS'

The court heard how the plot involved smuggling liquid bombs in soft drinks bottles onto planes bound for North America. A team of suicide bombers planned to assemble and detonate the hydrogen peroxide devices in mid-air.

The plot's ringleader, Abdulla Ahmed Ali, identified seven flights to San Francisco, Toronto, Montreal, Washington, New York and Chicago that left London within 2-1/2 hours of each other. Ali was jailed for life last September.

In his video, Ali said the attacks would be punishment from "the people of Islam" for Western attempts "to humiliate us, kill us and destroy us."

In the latest trial, the jury rejected the three men's defense that the plot was part of an elaborate publicity stunt.

Sue Hemming, head of the Crown Prosecution Service's counter-terrorism division, said the plot was intended "to cause death and injury on a massive scale."

"These men were involved in a calculated and sophisticated plot to create a terrorist event of major proportions," she said in a statement.