Eight Islamic fundamentalists planned to kill on an "unprecedented scale" by exploding bombs on transatlantic flights, a British court heard on Tuesday.
The men, who were arrested in August 2006 before they could carry out the alleged plot, had hoped for a "truly global impact", prosecutor Peter Wright told a London court.
Wright told Woolwich Crown Court that Abdulla Ahmed Ali and Assad Sarwar, both 28, led the group and were "indifferent to the carnage that was likely to ensue if their plans were successful."
The pair, along with 27-year-old Tanvir Hussain, 28-year-old Ibrahim Savant, 27-year-old Arafat Waheed Khan, 24-year-old Waheed Zaman, 30-year-old Umar Islam and 22-year-old Donald Stewart-Whyte, are charged with one count of conspiracy to murder.
Islam, Zaman, Khan, Savant and Stewart-Whyte stand accused of one additional count of conspiracy to murder.
The eight men deny all of the charges against them.
"What these men (Ahmed Ali and Sarwar) intended to bring about together and with others was a violent and deadly statement of intent that would have a truly global impact," Wright said.
"They intended, with others, to cause a series of co-ordinated explosions aboard a number of transatlantic passenger aircraft.
"The explosions were to be caused by the detonation in-flight of home-made bombs commonly referred to as improvised explosive devices."
Wright said the bomb components were designed to resemble soft drink bottles, batteries and other household items that could be disguised in their hand luggage so that they could be assembled on board.
"It is the Crown's case that these men and others were actively engaged in a most deadly plot designed to bring about what would have been, had they been successful, a civilian death toll from an act of terrorism on an almost unprecedented scale," he told the court.
The trial is expected to last 10 months.
The arrests in August 2006 led to worldwide restrictions on liquids that travellers can take on flights. Britain's terror alert level has remained on at least the second-highest of five levels since.